The Project Gutenberg eBook, Mental Philosophy: Including the Intellect, Sensibilities, and Will, by Joseph Haven

MENTAL PHILOSOPHY:

INCLUDING THE

INTELLECT, SENSIBILITIES, AND WILL.

BY

JOSEPH HAVEN, D. D., L. L. D.,

LATE PROF. OF SYSTEMATIC THEOLOGY IN THE THEOLOGICAL SEMINARY,
CHICAGO, ILL., AND LATE PROF. OF INTELLECTUAL AND MORAL
PHILOSOPHY IN AMHERST COLLEGE.

IMPROVED EDITION.

NEW YORK:
SHELDON AND COMPANY,
8 Murray Street.
1881

Dr. Haven's Valuable Series of School and
College Text-Books.

MENTAL PHILOSOPHY $2.00

MORAL PHILOSOPHY 1.75

HISTORY OF ANCIENT AND MODERN PHILOSOPHY. (In press).

Entered according to Act of Congress, in the year 1857, by
GOULD AND LINCOLN,
In the Clerk's office of the District Court Of the District of Massachusetts.

PREFACE.

If any apology were necessary for adding yet another to the numerous works on Mental Philosophy which have recently appeared, the circumstances that led to the preparation of the present volume may, perhaps, constitute that apology.

When called, several years since, to the chair of Mental and Moral Philosophy, in this Institution, the text-books, then in use, seemed to me not well adapted to the wants of College students. Nor was it easy to make a change for the better. Of the works in this department, then generally in use in our Colleges, some presumed on a more extensive acquaintance with the science than most young men at this stage of education are likely to possess; others, again, erring on the opposite extreme, were deficient in thorough and scientific treatment; while most, if not all, were, at the best, incomplete, presenting but a partial survey of the entire field. In none of them was the science of mind presented in its completeness and symmetry, in a manner at once simple, yet scientific; in none of them, moreover, was it brought down to the present time. Something more complete, more simple, more thorough, seemed desirable.

Every year of subsequent experience as a teacher has but confirmed this impression, and made the want of a book better adapted to the purposes of instruction, in our American Colleges, more deeply felt. The works on mental science, which have recently appeared in this country, while they are certainly a valuable contribution to the department of philosophy, seem to meet this deficiency in part, but only in part. They traverse usually but a portion of the ground which Psychology legitimately occupies, confining their attention, for the most part, to the Intellectual Faculties, to the exclusion of the Sensibilities, and the Will.

Feeling deeply the want which has been spoken of, it seemed to me, early in my course, that something might be done toward remedying the deficiency, by preparing with care, and delivering to the classes, lectures upon the topics presented in the books, as they passed along. This course was adopted—a method devolving much labor upon the instructor, but rewarding him by the increased interest and more rapid progress of the pupils. Little by little the present work thus grew up, as the result of my studies, in connection with my classes, and of my experience in the daily routine of the recitation and lecture room. Gradually the lectures, thus prepared, came to take the place more and more of a textbook, until there seemed to be no longer any reason why they should not be put into the hands of the student as such.

It is much easier to decide what a work on mental science ought to be, than to produce such a work. It should be comprehensive and complete, treating of all that properly pertains to Psychology, giving to every part its due proportion and development. It should treat the various topics presented, in a thorough and scientific manner. It should be conversant with the literature of the department, placing the student in possession, not only of the true doctrines, but, to some extent also, of the history of those doctrines, showing him what has been held and taught by others upon the points in question. In style it should be clear, perspicuous, concise, yet not so barren of ornament as to be destitute of interest to the reader.

At these qualities the writer has aimed in the present treatise; with what success, others must determine.

All science, in proportion as it is complete and true, becomes simple. In proportion as this result is attained, the labor bestowed upon it disappears from view, and the writer seems, perhaps, to others, to have said but a very plain and common thing. This is peculiarly the case with mental science. The difficulty of discussing with clearness and simplicity, and, at the same time, in a complete and thorough manner, the difficult problems of Psychology, will be understood only by those who make the attempt.

J. H.

CONTENTS.

INTRODUCTION.

INTRODUCTION

CHAPTER I.

ON THE NATURE AND IMPORTANCE OF MENTAL SCIENCE.

§ I.—Nature of the Science.

Mental Philosophy, what.—What is Mental Philosophy, as distinguished from other branches of science?

Philosophy, in the wide sense usually given it, denotes the investigation and explanation of the causes of things; it seeks to discover, and scientifically to state, the general laws both of matter and mind; its object is to ascertain facts, and their relation to each other. Mental Philosophy has for its object to ascertain the facts and laws of mental operation.

Metaphysics, what.—Of the two grand departments of human knowledge—the science of matter and the science of mind—the former, comprising whatever relates to material phenomena, the science of nature, is known under the general name of Physics; the latter, the science of mind, is often designated by the corresponding term, neither very correct nor very fortunate, Metaphysics. This term is often used to include whatever does not properly fall under the class of Physics. In its strict sense, it does not include so much, but denotes properly the science of abstract truth; the science of being, in itself considered—apart from its particular accidents and properties—that which we now call Ontology. The term is commonly ascribed to Aristotle, but incorrectly. It originated with his followers. Several treatises of his relating to natural science having been collected and published, under the title τα φυσικα, other treatises on philosophical subjects were afterward arranged under the title τα μεταφυσικα, indicating their relation to the former, as proper to be read after the perusal of those. Hence the term came into use in the general sense, already spoken of, to denote whatever is not included under physics although originally employed with a much more limited meaning.

Mental Philosophy not properly Metaphysics.—Neither in its wider nor in its stricter sense does this term properly designate the science of mind. Mental Philosophy neither embraces every thing not included under physics, nor is it the science of abstract being. As one of the intellectual, in distinction from the physical sciences, it holds a place along with Logic—the science of the laws of human thought and reasoning; Ethics—the science of morals; Politics—the science of human organization and government; to which should be added Ontology—the science of pure being; all which are properly embraced under the term Metaphysics in its wider and popular sense. To designate the science of mind in distinction from these other sciences, some more definite term is required. The word Psychology is now coming into use as such a term.

Mental Philosophy a Natural Science.—The science of mind, indeed, deserves in one aspect to be ranked among the natural sciences. It is a science resting on experience, observation, and induction—a science of facts, phenomena and laws which regulate the same. That which is specifically its object of investigation—the human mind—is strictly a part, and most important part of nature, unless we exclude man himself from the world to which he belongs, and of which he is lord.

Possibility of such a Science.—The possibility of the science of the human mind has been denied by some; but without good reason. If we can observe and classify the phenomena of nature, in her varied forms, animate and inanimate, and ascertain in this way the laws to which she is subject; if it is possible thus to construct a science of plants, of animals, of the elements that compose the substance of the earth, of the strata that lie arranged beneath its surface, of the forces and agencies that at any time, recent or remote, have been at work to produce the changes which have taken place upon and within our globe—nay, more, if leaving our own planet we may, by careful observation of the heavenly bodies, learn their places, movements, distances, estimate their magnitude and density, measure their speed, and thus construct a science of the stars, surely the phenomena of our own minds, the data of our own consciousness, must be at least equally within our reach, and equally capable of observation, classification, and scientific statement. If we can observe the habits of animals and plants, we can observe also the habits of men, and the phenomena of human thought and passion. If the careful induction of general truths and principles from observed facts form the basis and method of true science in the one case, so in the other.

Science of Matter and of Mind analogous.—The science of matter, and the science of mind agree perfectly in this, that all we know of either is simply the phenomena which they exhibit. We know not matter as it is in itself, but only as it affects our senses. We perceive certain qualities or properties of it, and these we embody in our definition, and beyond these we say nothing, because we know nothing. Equally relative is our knowledge of mind. What it is in itself we know not, but only its phenomena as presented to our observation and consciousness. It thinks and feels, it perceives, remembers, reasons, it loves, hates, desires, determines; these exercises are matter of experience and observation; they constitute our knowledge and our definition of mind, and beyond we cannot go.

Modes and Sources of Information the same in both.—This being the case, it is evident that both our sources of information, and our mode of investigation, must be essentially the same in the two departments of science. In either case our knowledge must be limited to phenomena merely, and these must be learned by observation and experience. A careful induction of particulars will place us in possession of general principles, or laws, and these, correctly ascertained and stated, will constitute our science, whether of matter or mind.

They differ in one Respect.—In one respect, indeed, our means of information with regard to the two branches of science differ. While both matter and mind can be known only by the observation of the phenomena which they present, in mental science the field of such observation lies in great part within ourselves—the phenomena are those of our own present or former consciousness—the mind is at once both the observer and the object observed. This circumstance, which at first seems to present a difficulty, is in reality a great advantage which this science possesses over all others.

Apparent Difficulty.—The difficulty which it seems to present is this: How can the eye perceive itself? How can the mind, as employed, for example, in remembering, or judging, or willing, inspect its own operations, since the moment its attention is turned to itself it is no longer engaged in that operation which it seeks to inspect—is no longer remembering, or judging, or willing, but is employed only in self-observation? We admit that the mind, in the very instant of its exercising any given faculty, cannot make itself, as thus engaged, the object of attention. But the operations of the mind, as given in consciousness, at any moment, may be retained or replaced by memory the next moment, and as thus replaced and attested, may stand before us the proper objects of our investigation, so long as we please. This puts it in the power of the mind to observe and to know itself.

Real Advantage.—The advantage accruing from the circumstance that the phenomena to be observed are those of our own present or former consciousness, is this: that those phenomena are fully within our reach, and also are capable of being known with greater certainty. In physical science the facts may be scattered over the globe, and over centuries of time, not personally accessible to any one observer in their completeness, and yet that completeness of observation may be essential to correct science. In psychology, the observer has within himself the essential elements of the science which he explores; the data which he seeks, are the data of his own consciousness; the science which he constructs is the science of himself.

Comparative Value of this kind of Knowledge.—The knowledge thus given in conscious experience is more correct and reliable than any other. It has this peculiarity that it cannot be disputed. I may be mistaken in regard to the properties of a piece of matter which I hold in my hand, and which seems to me to be square or round, of such or such a color, and of such or such figure, size, and density; but I cannot be mistaken as to the fact, that it seems to me to be of such color, figure, etc. The former are results of perception and judgment; the latter is an immediate datum of consciousness, and cannot be called in question. To doubt our own consciousness is to call in question our very doubt, since the only evidence of our doubting is the consciousness that we doubt. As to the phenomena of the external world—the things that are passing without—I may be mistaken; as to what is passing in my own mind—the thoughts, feelings, volitions of my own conscious self—there is no room for doubt or mistake.

Not limited to Consciousness.—I do not mean, by what has been said, to imply that in our own observation of mental phenomena we are limited to the experience of our own minds, but only that this is the principal source of our information. The mental operations of others, so far as we have access to their minds, are also legitimate data. These we may observe for ourselves in the daily intercourse of life, may notice how, under given circumstances, men will think, feel, and act, and the knowledge thus acquired will constitute a valuable addition to our self-knowledge. We may receive also, in this science, as in any other, the testimony of others as to their own mental states and operations. In so far as psychology relies upon these sources, it stands on a footing with other sciences.

§ II.—Importance of Mental Science.

Comparative Neglect.—That the science of the mind has not hitherto held that high place in the public regard and estimation, at least in our own country, to which it is justly entitled, as compared with other branches of knowledge, can hardly be denied. The cause of this comparative neglect is to be found partly in the nature of the science itself, partly in the exclusively practical tendencies of the age.

The first Cause considered.—The nature of the science is such that its benefits are not immediately apparent. The dullest mind can perceive some use in chemistry, or botany, or natural philosophy. They are of service in the analysis of soils, the rotation of crops, the comprehension of the laws of mechanical and chemical forces. But mental science has no such application, no such practical results patent and obvious to the careless eye. Its dwelling-place and sphere of action lie removed somewhat from the observations of men. It has no splendid cabinets or museums to throw open to the gaze of the multitude. It cannot arrange in magnificent collection all the varieties of mental action, all the complications of thought and feeling as yet observed, nor illustrate by curious instruments, and nice experiments, the wonderful laws of association, the subtle changes and swift flashes of wit and fancy, and quick strong emotion, the impulses of desire, the curious play of volition, the unexplained mystery of thought, the lights and shadows that come and go upon the field of consciousness. For these curious and wonderful phenomena of the inner life there are no philosophic instruments or experiments, no charts or diagrams. Nor are there yet brilliant discoveries to be made, nor splendid rewards to be gained by the votaries of this science. "Four or five new metals," says Sydney Smith, "have been discovered within as many years, of the existence of which no human being could have had any suspicion; but no man that I know of pretends to discover four or five new passions."

The second Cause.—But the chief obstacle, as I suppose, to the more general cultivation of mental science is to be found in the exclusively practical tendencies of the age. We are a people given more to action than to thought, to enterprise than to speculation. This is perhaps inseparable from the condition of a new state. An age of action is seldom an age of reflection. External life demands the energies of a new people. The elements are to be subdued, mountains levelled, graded, tunnelled, roads constructed, cities built, and many useful, necessary works to be wrought with toil and cost, before that period comes of golden affluence, and leisure, and genial taste, and elegant culture, that can at once appreciate and reward the higher efforts of philosophic investigation.

Relation to other Sciences.—The importance of mental science appears from its relation to other sciences. We find in nature a gradually ascending series. As we pass from the observation and study of the mineral to the forms of vegetable life, from the plant to the insect—and thence to the animal, and from the animal, in his various orders and classes, to man, the highest type of animated existence on the earth, we are conscious of a progression in the rank and dignity of that which we contemplate. But it is only when we turn our attention from all these to the intelligence that dwells within the man, and makes him master and lord of this lower world, that we stand upon the summit of elevation and overlook the wide field of previous inquiry. Toward this all other sciences lead, as paths along the mountain side, starting from different points, and running in different directions, converge toward a common terminus at the summit. As the mineral, the plant, the insect, the animal, in all their curious and wonderful organizations, are necessarily inferior to man, so is the science of them, however important and useful, subordinate to the science of man himself; and as the human body, curious and wonderful in its organism and its laws, is nevertheless inferior in dignity and worth to the spirit that dwells within, and is the true lord of this fair castle and this wide and beautiful domain, so is the science of the body, its mechanism, its chemistry, its anatomy, its laws, inferior to the science of the mind, the divinity within.

Other Sciences Creations of the Mind.—Many of the sciences justly regarded as the most noble, are themselves the creations of the mind. Such, for example, is the science of number and quantity—a science leading to the most sublime results, as in the calculations of the astronomer, yet a pure product of the human intellect. Indeed what is all science but the work of mind? The creations of art are wonderful, but the mind that can conceive and execute those creations is still more to be admired. Language is wonderful, but chiefly as a production and expression of mind. The richness, the affluence, the eloquence, the exactness, the beauty, for example, of the Greek tongue, of what are these the qualities, and where did they dwell—in the Greek language, or in the Greek mind? Which is really the more noble and wonderful then, the language itself, or the mind that called into being such a language, and employed it as an instrument of expression; and of which is the science most noble and worthy of regard?

We admire the genius of a Kepler and a Copernicus, we sympathize with their enthusiasm as they observe the movements and develop the laws of the heavenly bodies; we look through the telescope, not without a feeling of awe, as it seems to lift us up, and bear us away into the unknown and the infinite, revealing to us what it would almost seem had never been intended for the human eye to see; but one thing is even more wonderful than the telescope—that is the mind that contrived it. One thing is more awe-inspiring than the stars, and that is the mind that discovers their hidden laws, and unlocks their complicated movements; and when we would observe the most curious and wonderful thing of all, we must leave the tubes and the tables, the calculations and the diagrams with which the man works, and study the man himself, the workman.

Relation of this Science to the practical Arts and Sciences.—But aside from the view now presented, the connection of mental science with other and practical arts and sciences is much more intimate than is usually supposed. Take for example the very noblest of all sciences—theology; we find it, in an important sense, based upon and receiving its shape and character from the views which we entertain, and the philosophy which we adopt of the human mind. Our philosophy underlies our theology, even as the solid strata that lie unseen beneath the surface give shape and contour and direction to the lofty mountain range.

Psychology as related to Theology.—Not to speak of the very idea which we form of the divine Being, borrowed as it must be, in a sense, from our previous conception of the human mind, and our own spiritual existence, not to speak of the arguments by which we seek to establish the existence of the divine Being, involving as they do some of the nicest and most important of the laws of human thought, what problems, we may ask, go deeper into the groundwork of any theological system than those pertaining to human ability, and the freedom of the will—the government of the affections and desires—the power of a man over himself, to be other and better than he is, and to do what God requires. But these are questions purely psychological. You cannot stir a step in the application of theology to practical life, till you have settled in some way these questions, and that view, whatever it be, crude or profound, intelligible or absurd, is, for the time, your science, your philosophy of the mind.

Psychology as related to the healing Art.—Scarcely less intimate is the connection of psychology with the science of life. The physician finds in the practice of his profession, that in order to success, the laws of the human mind must constitute an important part of his study—how to avoid, and how to touch, the secret springs of human action. A word rightly spoken is often better than a medicine. In order to comprehend the nature of disease he must understand the effect on the bodily organization of the due, and also of the undue, exertion of each of the mental faculties; in fine, the whole relation of the mind to the bodily functions, and its influence over them—a field of inquiry as yet but imperfectly understood, if indeed adequately appreciated by the medical profession.

As related to Oratory.—To the public speaker, whether at the bar, in the public assembly, in the halls of legislation, or in the pulpit, it need hardly be said that a knowledge of this science, and the ability to make practical use of it, is indispensable. Success in oratory depends, doubtless, in a measure, upon other things; but he who best understands the laws and operations of the human mind, how to touch the sensibilities, how to awaken the passions, how to excite the fears and the hopes, how to rouse the resentment of his hearers, how to soothe the troubled spirits, and allay the excitement of feeling, and disarm prejudice, and call into play the sober reason and calm judgment of man, will best be able to accomplish his purpose. He will be able to turn to his own account the circumstances of the occasion, and like a skillful organist, touch with ease, yet with precision and effect, what key he will. No man can do this who does not well understand the instrument.

As related to the Art of Education.—Especially is this science of use to the teacher in the knowledge which it gives him of the mind of his pupil, and the skill in dealing with that mind. The mind of the pupil is to him the instrument on which he is required to play—a curious instrument of many and strange keys and stops—capable of being touched to wonderful harmony, and to fearful discord;—and to handle this instrument well is no ordinary acquirement. What shall we say of the man who knows nothing of the instrument, but only the music to be performed, nothing of the mind to be taught, but only the knowledge to be communicated? To know the mind that is to be taught, how to stimulate, how to control, how to encourage, how to restrain, how to guide and direct its every movement and impulse, is not this the very first and chief thing to be known?

Connection of this Science with our own personal Interests.—The importance of mental science is evident not only from its relation to other sciences, but from the relation it sustains to man and his higher interests. Some sciences interest us as abstractions—merely speculative systems of truth; others as realities, but of such a nature, and so remote from the personal interests and wants of the race to which we belong, that they make little appeal to our sensibilities. Thus it is with mathematical and astronomical truth. The heavenly bodies, whose movements we observe, hold on their swift silent way, in the calmness of their own eternity, regardless of man and his destiny, even as they rolled ages ago, and as they will ages hence. What have we to do with them or they with us? We watch them as they hold their course through the deep firmament, as children, standing on the sea-side, watch the distant snowy sail that glides silently along the horizon, afar off, beautiful, unknown. So sail those swift ships of the firmament, and only he who made them knows their history.

Psychology in contrast with other Sciences in this respect.—But when we come to the study of ourselves, and the laws of our own intelligence, our inquiries assume a practical importance which attaches to no other departments of truth. It is no longer the sail dimly visible on the far horizon, but our own conscious being that is the object of thought. The question no longer is, Whence comes that swift ship, and whither goes it, but, What am I, and whither going; what my history, and my destiny? This mysterious soul which animates me, and is the presiding divinity over all my actions, what is it, with all its wondrous faculties—sense, imagination, reason, will—those powers of my being? What is that change which passes upon me, which men call sleep, and that more mysterious and fearful change that must soon pass upon me, and that men call death? How is it that events of former years come back to mind, with all the freshness and reality of passing scenes? What is that principle of my nature that ever assumes to itself the right of command, saying to all my inclinations and passions, thou shalt, and thou shalt not, and when I disobey that mandate, filling my whole soul with misery, my whole future existence with remorse? And what and whence that word ought, that has so much to do with me and my pursuits: ought what, and why ought, and to whom?—Am I free, or am I subject to inevitable necessity; if free, then how are all my actions controlled, and predetermined by a divine Providence? If not free, then how am I responsible? Who shall solve this problem; who shall read me this strange inexplicable riddle of human life? Such are the questions and themes which mental philosophy discusses, and we perceive at a glance their intimate connection with the highest interests and personal wants of man as an individual.

Connection of this Science with mental Discipline.—The importance of mental science may be further apparent in its effect on the culture and discipline of the mind. It is the peculiar effect of this science to sharpen and quicken the mental powers, to teach precision and exactness of thought and expression, to train the mind to habits of close attention and concentration of thought, to lead it to inquire into the causes and relations of things; in a word, to render it familiar with the great art of distinguishing things that differ. It would hardly be possible to name another branch of study that tends so directly to produce these results in the cultivation of the mind.

CHAPTER II.

ANALYSIS AND CLASSIFICATION OF THE MENTAL POWERS.

Importance of such a preliminary Investigation.—It is of the highest importance, as we approach a science like the one before us, to obtain, if possible, at the outset, a clear and comprehensive view of the field about to be explored. It is desirable that the traveller, before entering a new country, should learn something respecting its extent, its political and geographical divisions, its manners, its laws, its history. Even more necessary is it, in entering upon a new science, to know its boundaries and divisions, to obtain a clear idea, at the very commencement of our inquiries, of the number, nature, extent, and arrangement of the subject we are about to investigate. Otherwise we shall be liable to confusion and error, shall not know where, at any moment, in the wide field of investigation, we may chance to be, or what relation the topic of our immediate inquiry holds to the whole science before us; as a ship on the ocean, without observation and reckoning, loses her latitude and longitude. We shall be liable to confound those distinctions which are of less, with those which are of more importance, and to mistake the relation which the several topics of inquiry bear to each other. Especially is this previous survey and comprehension of the subject essential in a science like this, where so much depends on the clearness and accuracy with which we distinguish differences often minute, and on the definiteness with which we mark off and lay out the several divisions of our work. A thorough analysis and classification of the various faculties of the mind is necessary, in the first place, before we enter upon the special investigation of any one of them. Such a classification must serve as our guide-book and chart in all further inquiries.

Difficulty of such an Investigation.—The importance of such a preliminary investigation is scarcely greater than its difficulty. It would be easy, indeed, to mention, almost at random, a considerable number of mental operations, with whose names we are familiar; and a little thought would enable us to enlarge the list almost indefinitely. But such a list, even though it might chance to be complete, would be neither an analysis nor a classification of these several powers. It would neither teach us their relations to each other and to the whole, nor enable us to understand the precise nature and office of each faculty. We could not be sure that we had not included under a common name operations essentially different, or assigned distinct places and offices to powers essentially the same. Much depends, moreover, on the order in which we take up the several faculties.

It is evident at a glance that to form a clear, correct, and comprehensive arrangement of the powers of the mind, is no slight undertaking. A complete understanding of the whole science of the mind is requisite. It is one of the last things which the student is prepared to undertake, yet one of the first which he requires to know. Unfortunately for the science, perhaps no topic in the whole circle of intellectual investigation has been more generally neglected, by those who have undertaken to unfold the philosophy of the mind, than the one now under consideration.

§ I.—General Analysis.

A mental Faculty, what.—In making out any scheme of classification, the question at once arises, how are we to know what are, and what are not distinct faculties? In order to this, we must first determine what constitutes a mental faculty.

What, then, is a faculty of the mind? I understand by this term simply the mind's power of acting, of doing something, of putting forth some energy, and performing some operation. The mind has as many distinct faculties, as it has distinct powers of action, distinct functions, distinct modes and spheres of activity. As its capabilities of action and operation differ, so its faculties differ.

The Mind not complex.—Now mental activity is, strictly speaking, one and indivisible. The mind is not a complex substance, composed of parts, but single and one. Its activity may, however, be exercised in various ways, and upon widely different classes of objects; and as these modes of action vary, we may assign them different names, and treat of them in distinction from each other. So distinguished and named, they present themselves to us as so many distinct powers or faculties of the mind. But when this is done, and we make out, for purposes of science, our complete list and classification of these powers, we are not to forget that it is, after all, one and the same indivisible spiritual principle that is putting forth its activity under these diverse forms, one and the same force exerting itself—whether as thinking, feeling, or acting—whether as remembering, imagining, judging, perceiving, reasoning, loving, fearing, hating, desiring, choosing. And while we may designate these as so many faculties of the mind, we are not to conceive of them as so many constituent parts of a complex whole, which, taken together, compose this mysterious entity called the mind, as the different limbs and organs of the physical frame compose the structure called the body. Such is not the nature of the mind, nor of its faculties.

The Question before us.—In inquiring, then, what are the faculties of the mind, we have simply to inquire what are the distinct modes of its activity, what states and operations of the mind so far resemble each other as to admit of being classed together under the same general description and name. Our work, thus understood, becomes in reality a very simple one.

The more important Distinctions to be first ascertained.—What, then, are the clearly distinct modes of mental activity? And first let us endeavor to ascertain the wider and more important distinctions. We shall find that, innumerable as the forms of mental activity may at first sight appear, they are all capable of being reduced to a few general and comprehensive classes.

The first Form of mental Activity.—I sit at my table. Books are before me. I open a volume, and peruse its pages. My mind is occupied, its activity is awakened; the thoughts of the author are transferred to my mind, and engage my thoughts. Here, then, is one form of mental activity. This one thing I can do; this one power I have—the faculty of thought.

The second Form.—But not this alone: I am presently conscious of something beside simple thought. The writer, whose pages I peruse, interests me, excites me; I am amused by his wit, moved by his eloquence, affected by his pathos; I become indignant at the scenes and characters which he portrays, or, on the contrary, they command my admiration. All this by turns passes over me as the fitful shadows play upon the waters, coming and going with the changing cloud. This is not pure thought. It is thought accompanied with another and quite distinct element, that is, feeling. This power also I have;—I can feel.

A third Form.—And not this alone. The process does not end here. Thought and feeling lead to action. I resolve what to do. I lay down my book, and go forth to perform some act prompted by the emotion awakened within me. This power also I have;—the faculty of voluntary action, or volition.

These three Forms comprehensive.—Here, then, are three grand divisions or forms of mental activity—thought, feeling, volition. These powers we are constantly exerting. Every moment of my intelligent existence I am exercising one or another, or all of these faculties. And, what is more, of all the forms of mental activity, there is not one which does not fall under one or another of these three divisions—thought—feeling—volition. Every possible mental operation may be reduced to one of these three things.

We have, then, these grand departments or modes of mental activity, comprehensive of all others: Intellect, or the faculty of simple thought; Sensibility, or the faculty of feeling; Will, or the faculty of voluntary action.

Under these leading powers are comprehended subordinate modes of mental activity, known as faculties of the Intellect, or of the Sensibility, or of the Will.

We have at present to do only with those of the Intellect.

§ II.—Analysis of Intellectual Powers.

Sense-perception.—Observing closely the intellectual operations of the mind, we find a large class of them relating to objects within the sphere of sense, external objects, as perceived by the senses. The mind, through the medium of sense, takes direct cognizance of these objects. This class of operations we may call Sense-perception, and the faculty thus employed, in distinction from other leading divisions of the intellectual powers, we may call Sense, or the Presentative faculty. Its distinctive office is to present to the mind, through the senses, objects external, sensible, as now and here present.

The Representative Power.—But the mind not only receives impressions of external objects, as present, and acting on the organs of sense; it has also the faculty of conceiving of them in their absence, and representing them to itself. This faculty, as distinguished from the receptive power, or sense, we may call the Representative Power.

Mental Reproduction, and mental Recognition as distinguished.—This power operates in various forms. There may be the simple representation of the absent object, without reference to the act of former perception, as when I think of the Strasburg tower, without recalling any particular instance of its perception. Or there may be such recalling of the former act and instance of perception. The thought of the tower, as it presents itself to my mind, may stand connected definitely with the idea of the time, and place, and attending circumstances in which, on some occasion, I saw that object. It is then recognized as the object which was seen at such or such a time. The former is an instance of mental reproduction simply—the latter, of mental recognition. We have in common language but one name for the two—although the term mare strictly belongs only to the latter—and that is, Memory.

Representation of the Ideal in distinction from the Actual.—Again, unlike either of these, there may be a conception and representation of the object, not at all as it is in reality, and as it was perceived, but varied in essential particulars, to suit our own taste and fancy—a tower not of ordinary stone, but of some rare and costly marble—not of ordinary height, but reaching to the skies, etc., etc. In the former cases we conceived only of the actual, now of the ideal. This faculty is called Imagination. Both are forms of the representative power, not presenting, but only representing objects.

Conception of the Abstract.—The Discursive or Reflective Power.—In the cases thus far described we have conceived of some sensible object, considered in and by itself, capable of being represented to thought. We may, however, conceive not of an object in itself considered, but of the properties and relations of objects in the abstract. Thus we compare and class together those objects which we perceive to possess certain properties in common; as books bound in cloth, or in leather, octavos, or duodecimos. In so doing we exercise the faculty of generalization, which involves comparison, and also what is usually termed abstraction. Or we may reverse the process, and instead of classing together objects possessing certain elements in common, we may analyze a complex idea, or a comprehensive term, in order to derive from it whatever is specifically included in it. Thus from the general proposition, "All men are mortal," inasmuch as the term "all men" includes Socrates, I infer that Socrates is mortal. The process last named is called reasoning.

In either case, both in the synthetic and the analytic process now described, we are dealing not with the concrete but the abstract. The properties and relations of things, rather than things themselves, are the objects of our thoughts. Still they are the properties and relations primarily of sensible objects, and of these objects as conceived, and not as presented to sense. To distinguish this class of conceptions from those previously considered, and also from that presently to be noticed, we may designate this power of the mind as the Discursive or Reflective Power. Its results are notions of the understanding rather than impressions of sense, or ideas of reason.

Conceptions not furnished by Sense.—The Intuitive Power.—We have considered thus far those intellectual operations which fall within three leading departments of mental activity;—the Presentative, Representative, and Discursive Powers. These operations all have reference directly or indirectly to sensible objects. The first regards them as present; the second represents them as absent; the third considers their properties and relations in the abstract.

But the mind has also the faculty of forming ideas and conceptions not furnished by the senses. It departs from the sphere of sense, and deals with the super-sensible, with those primary ideas and first principles presupposed in all knowledge of the sensible. Such are the ideas of time, space, cause, the right, the beautiful. These are suggested by the objects of sense, but not directly derived from nor given by those objects. They are ideas of reason, rather than notions of understanding. They are awakened in the mind on occasions of sensible perception, but not conveyed to the mind through the senses, as in perception, nor directly derived from the object as in the case of the representative and discursive powers. This faculty we may call the Originative or Intuitive Power, in distinction from those previously considered.

Summary of leading Divisions.—We have then four grand divisions of intellectual operations, under which the several specific faculties arrange themselves; viz., the Presentative, the Representative, the Discursive, and the Originative or Intuitive faculty. The first has to do with sensible objects, as present; the second has to do with the same class of objects as absent; the third deals with their abstract properties and relations; and the fourth has to do not with the sensible, in any form, but with the super-sensible.

I believe the faculties of the intellect, in pure thinking, may all be reduced to those forms now specified, under these four leading divisions.

Results of the preceding analysis in a tabular form:

POWERS OF THE INTELLECT.

§ III.—Historical Sketch—Various Divisions of the Mental Faculties.

The earlier Division.—The general division of the powers of the mind, for a long time prevalent among the earlier modern philosophers, was into two chief departments, known under different names, but including under the one what we now term the intellect, under the other what we designate as the sensibilities and the will, which were not then, as now, distinguished from each other in the general division, but thrown into one department. Under the first of these departments, they included the thinking and reasoning powers, the strictly intellectual part of our nature; under the second, whatever brings the mind into action—the impelling and controlling power or principle—the affections, emotions, desires, volitions, etc. The names given to these two divisions varied with different writers, but the difference was chiefly in the name, the principle of division being the same. By some authors they were designated as the contemplative and the active powers, by others cognitive and motive. The latter was the nomenclature proposed by Hobbes. Others again adopted the terms understanding and will, by which to mark the two divisions; Locke, Reid, some of the French philosophers, and, in our own country, Edwards, followed this division. Stewart designates them, the one class as the intellectual, and the other as the active and moral powers. Brown objects to this phraseology on the ground that the intellectual powers are no less active than the other. He divides the mental powers or states primarily into what he calls external and internal affections of the mind, comprehending under the former all those mental states which are immediately preceded by and connected with the presence of some external object; under the latter, those states which are not thus immediately preceded. The latter class he divides into intellectual states and emotions, a division corresponding essentially to those of the authors previously mentioned, the emotions of Brown comprehending essentially the powers which others had termed motive, or active and moral.

Prevalence of this Method.—This twofold division of the mental powers, under different names, as now stated, has been the one generally prevalent until a comparatively recent date. It may doubtless be traced, as Sir William Hamilton suggests, to a distinction made by Aristotle, into cognitive and appetent powers.

The more recent Method.—The threefold division of the mental faculties very early came into use among philosophical and theological writers in this country, and is now very generally adopted by the more recent European writers of note, especially in France and Germany. According to this division the various affections and emotions constitute a department by themselves, distinct from the will or the voluntary principle. There are many reasons for such a distinction; they have been well stated by Professor Upham Cousin adopts and defends the threefold division, and previously still, Kant, in Germany, had distinguished the mental powers under the leading divisions of intelligence, sensibility, and desire.

MENTAL PHILOSOPHY.

DIVISION FIRST.
THE INTELLECTUAL FACULTIES.

PRELIMINARY TOPICS.

CHAPTER I.

CONSCIOUSNESS.

General Statement.—Before proceeding to investigate the several specific faculties of the intellect, as already classified, there are certain preliminary topics to be considered, certain mental phenomena, or mental states, involved more or less fully in all mental activity, and on that account hardly to be classed as specific faculties, yet requiring distinct consideration. Such are the mental states which we denominate as consciousness and attention.

Definitions.—Consciousness is defined by Webster as the knowledge of sensations and mental operations, or of what passes in our own minds; by Wayland, as that condition of the mind in which it is cognizant of its own operations; by Cousin, as that function of the intelligence which gives us information of every thing which takes place in the interior of our minds; by Dr. Henry, translator of Cousin, as the being aware of the phenomena of the mind—of that which is present to the mind; by Professor Tappan, as the necessary knowledge which the mind has of its own operations. These general definitions substantially agree. The mind is aware of its own operations, its sensations, perceptions, emotions, choices, etc., and the state or act of being thus cognizant of its own phenomena we designate by the general term Consciousness.

Reasons for regarding Consciousness as not a distinct Faculty.—Is this, however, a distinct faculty of the mind? The mind, it is said, is always cognizant of its own operations: when it perceives, it is conscious of perceiving; when it reasons, it is conscious of reasoning; when it feels, it is conscious of feeling; and not to be conscious of any particular mental act, is not to perform that act. To have a sensation, and to be conscious of that sensation, it is said, are not two things, but one and the same, the difference being only in name. A perception is indivisible, cannot be analyzed into a fact, and the consciousness of the fact, for the perception is an act of knowing, and does not take place if it be not known to take place. This is the view taken by Sir William Hamilton, Professor Bowen, and others of high authority. It was maintained by Dr. Brown with much force as an objection to the doctrine of Reid, who had recognized consciousness as a distinct faculty.

Reasons for the opposite View.—On the other hand, the claims of this form of mental activity to be regarded as a faculty of the mind, distinct from and coördinate with the other mental powers, are admitted and maintained by writers of authority, among whom are Dr. Wayland and President Mahan. They maintain that the office of consciousness being to give us knowledge of our own mental states, and this function being quite distinct from that of any other mental faculty, the capacity or power of performing this function deserves to be regarded as itself a faculty of the mind. It is maintained also by Dr. Wayland that consciousness does not necessarily invariably accompany all mental action, but that there may be, and are, acts of which we are not at the time conscious.

Instances in proof of this Position.—In support of this position he refers to certain cases as instances of unconscious perception; as when, for example, a clock strikes within a few feet of us, while we are busily engaged, and we do not notice it, or know that it has struck, yet if questioned afterward, are conscious of an impression that we have heard it; as when also while reading aloud to another person, some thought arrests our attention, and yet by a sort of mechanical process, we continue the reading, our mind, meanwhile, wholly occupied with another subject, until presently we are startled to find that we have not the remotest conception of what we have just been reading; yet we read every word correctly, and must, it would seem, have perceived every word and letter. He refers also to the case of the short-hand writer to the House of Lords in England, who, on a certain occasion, while engaged in taking the depositions of witnesses in an important case, after many hours of continued exertion and fatigue, fell, for a few moments, into a state of entire unconsciousness, yet kept on writing down, and that with perfect accuracy, the depositions of the witness. Of the last few lines, when he came to read them, he had no recollection whatever, yet they were written as legibly and accurately as the rest. From these and similar cases it is inferred that there may be mental activity of which we have at the time no consciousness.

The Evidence examined.—With regard to the cases now cited, it seems to me that they do not fully establish the point in question. For in the first place, it may be doubted whether they really involve any mental activity—whether they are properly mental acts, and not merely mechanical or automatic. It is well known that many processes which ordinarily require more or less attention may, when they have become perfectly familiar, be carried on for a time almost without thought. The senses, so far as they are required to act at all, seem in such cases to act mechanically or automatically, somewhat as a wheel when once set in motion continues for a time to revolve by its own momentum, after the propelling force is withdrawn. The mental activity exerted in such cases, if there be any, is so very slight as to escape attention, and we are unconscious of it simply because there was little or nothing to be conscious of. We have an illustration of this in the act of walking, while busily engaged in conversation with a friend, or in our own meditations. We are not conscious of any mental act preceding or directing each step and movement of the limbs, but having at the outset decided what direction to take, the mind gives itself to other matters, while the process of walking goes on by a sort of mechanical impulse, until presently something occurs to arrest our attention and direct it to the physical movement in which we are engaged. The muscular contractions tend to follow each other in a certain regular succession; a certain law of association seems to govern their movements, as is seen in the rapid motions of the pianist, the flute player, the type distributor, and in many similar cases; and so long as the regular succession, and accustomed order of movement, is undisturbed, the process goes on with little or no interference of the intellectual principle. In such cases the act can hardly be said to involve mental activity.

A further Question.—But aside from this, even admitting that the acts under consideration are such as to involve mental activity, what evidence is there, it may still be asked, that there was at the moment no consciousness of that activity? That there was subsequently no consciousness of it, does not make it certain that there was none at the time. The subsequent consciousness of an act is neither more nor less than memory, and is not properly consciousness at all. Consciousness takes cognizance, properly speaking, only of the present, not of the past. The absence of subsequent consciousness is simply absence of memory, and this may be accounted for in other ways than by supposing a total absence of consciousness in the first instance. Whatever mental activity was really exerted by the short-hand reporter in the case referred to, he was, doubtless, conscious of exerting at the time, but it may have been so slight, and the mind so little impressed by it, in the state of physical weariness and prostration, that it was not remembered a moment afterward. We remember not every thing that occurs, but only that to which we attend, and which makes some impression upon us.

The true Explanation.—In the other cases referred to, the explanation now given is still more evidently the true one. What is called an absence of consciousness is simply an absence of attention at the time, and consequently of memory afterward. The person who is reading aloud, in the case supposed, is mentally occupied with something else than the sentiments of the author, is not attending, in a word, to what he is reading, and hence does not, a moment after, remember what it was that he read. So of the striking of the clock. The sound fell upon the ear, the auditory nerve performed its office, the usual change, whatever it may be, was produced in the brain, but the process of hearing went no further; either no mental activity was awakened by that sound, or, if any, but the slightest, for the mind was otherwise occupied, in a word, did not attend to the summons of the messenger that waited at the portal, and hence there was no subsequent remembrance of the message, or at most a vague impression that something of the kind was heard.

On the whole, it does not appear from the cases cited, that mental activity is ever, at the moment of its exertion, unaccompanied with consciousness.

Summary of the Argument.—I hesitate then to assign consciousness a place among the faculties of the mind, as distinct from and coördinate with them, for the following reasons:

1. It seems to me to be involved in all mental acts. We cannot, as it has been already said, suppose an act of perception, for example, or of sensation, without the consciousness of that perception or sensation. Whatever the mind does, it knows that it does, and the knowing is involved in and given along with the doing. Not to know that I see a book, or hear a sound, is in reality not to see and not to hear it. Not to know that I have a sensation is not to have it. But what is involved in all mental action cannot be set down by itself as a specific mental act. This were much the same as to reckon the whole among the parts.

2. Consciousness, while involved in, cannot be, either psychologically or chronologically, distinguished from the mental acts which it accompanies. The act and the consciousness of the act are inseparable in time, and they are incapable of being distinguished as distinct states of mind. We cannot break up the sensation or perception into a fact, and the consciousness of that fact. Logically we may distinguish them as different objects of thought and attention, but not psychologically as distinct acts of mind.

3. Consciousness is not under the control of the will, and is not therefore a faculty of the mind. It is not a power of doing something, but an inseparable concomitant of all doing. What has been termed by some writers voluntary consciousness, or reflection, is simply attention directed to our own mental acts.

Distinction of Consciousness and Self-Consciousness.—Others again distinguish between consciousness and self-consciousness; but all consciousness, properly so called, involves the idea of self or the subjective element. To know that I have a sensation is virtually to know myself as having it.

Cases of abnormal or suspended Consciousness.—In certain disordered and abnormal states of the nervous organism, the knowledge of what has transpired previously to that state seems to be lost; and then again, on passing out of that condition into the normal one, all knowledge of what took place while in the abnormal state is wanting. Instances are on record where persons have alternated in this manner from one to the other condition, carrying on, as it were, by turns, two separate and independent lines of mental activity. An instance of this nature is related by Dr. Wayland. It has been usual to speak of these as instances of disordered or suspended consciousness. Strictly speaking, however, it is not consciousness but memory that is in such cases disordered. It is not the knowledge of the present, but of the past, that is disturbed and deficient. While the abnormal state continues, the individual is conscious of what transpires in that state. When it ceases, the patient wakes as from a reverie or dream, and retains no recollection of any thing that took place during its continuance. It is the memory that fails, and not the consciousness. We are never conscious of the past.

Objects of Consciousness.—1. Consciousness deals only with reality. We are conscious only of that which is, not of that which may be. The poet is conscious indeed of his fiction, the builder of air-castles is conscious of his reverie, but the fiction and the reverie, regarded as mental acts, are realities, and it is only as mental acts that they are objects of consciousness.

2. Not every thing real is an object of consciousness, but only that which is present and in immediate relation to us. The destruction of Pompeii, and the existence of an Antarctic continent are realities, but not objects of my consciousness.

3. Primarily and directly we are conscious of our own mental states and operations; of whatever passes over the field of our mental vision, our thoughts, feelings, actions, physical sensations, moral sentiments and purposes: mediately and indirectly we are conscious of whatever, through the medium of sense, comes into direct relation to us. For instance, when I put forth my hand and it strikes this table, I am conscious not only of the movement, and the effort to move, but of the sensation of resistance also, and indirectly I may be said to be conscious not of the resistance only, but of something—to wit, the table—as resisting. This something I know, as really as I know the sensation and the fact of resistance. To this immediate perception of the external world in direct relation to our physical organism, Sir W. Hamilton would extend the sphere of consciousness. Usually, however, the term has been employed in a more restricted sense—to denote the knowledge of what passes within, rather than of what lies without the mind itself.

CHAPTER II.

ATTENTION.

General Character of this Power.—It has not been usual to treat of Attention as one of the distinct faculties of the mind. It is doubtless a power which the mind possesses, but like the power of conception, or more generally the power of thought and mental apprehension, it is involved in and underlies the exercise of all the specific mental faculties. Nor is it, like consciousness, confined to a distinct department of knowledge, viz., the knowledge of our own mental states. It is subsidiary to the other mental powers, rather than a faculty of original and independent knowledge. It originates nothing—teaches nothing—puts us in possession of no new truth—has no distinct field and province of its own. And yet without it other faculties would be of little avail.

Definitions.—If it were necessary to define a term so well understood, we might describe it as the power which the mind has of directing its thoughts, purposely and voluntarily, to some one object, to the exclusion of others. It is described by Dr. Wayland as a sort of voluntary consciousness, a condition of mind in which our consciousness is excited and directed by an act of the will. He speaks also of an involuntary attention, a state of mind in which our thoughts, without effort or purpose of our own, are engrossed by objects of an exciting nature. It may be questioned, perhaps, whether this is properly attention. Only in so far as attention is a voluntary act is it properly a power of the mind, and only in so far does it differ from the simple activity of thought, or of consciousness. The latter is always involuntary, and in this it differs from attention.

Instances in Illustration.—It can hardly be necessary to illustrate by example the nature of a faculty so constantly in exercise. Every one perceives, for instance, the difference between the careless perusal of an author—the eye passing listlessly over the pages, and the mind receiving little or no impression from its statements—and the reading of the same volume with fixed and careful attention, every word observed, every sentiment weighed, and the whole mental energy directed to the subject in hand. We pass, in the streets of a crowded and busy city, many persons whom we do not stop to observe, and of whose appearance we could afterward give no account whatever. Presently, some one in the crowd attracts our notice. We observe his appearance, we watch his movements, we notice his peculiarities of dress, gait, manners, etc., and are able afterward to describe them with some degree of minuteness. In the former case we perceive, but do not attend. In the latter, we attend, in order to perceive.

Sometimes the sole Occupation.—Attention seems to be at times the sole occupation of the mind for the moment, as when we have heard some sound that attracts our notice, and are listening for its repetition. In this case the other faculties are for the time held in suspense, and we are, as we say, all attention. The posture naturally assumed in such a case is that indicated by the etymology of the word, and may have suggested its use to designate this faculty, viz., attention—ad-tendo—a bending to, a stretching toward, the object of interest.

Analysis of the mental Process in Attention.—If we closely analyze the process of our minds in the exercise of this power, we shall find, I think, that it consists chiefly in this—the arresting and detaining the thoughts, excluding thus the exercise of other forms of mental activity, in consequence of which the mind is left free to direct its whole energy to the one object in view. The process may be compared to the operation of the detent in machinery, which checks the wheels that are in rapid motion, and gives opportunity for any desired change; while it may be compared, as regards the result of its action, to the helm that directs the motion of the ship, now this way, now that, as the helmsman wills.

Objects of Attention.—The objects of attention are of course as various as the objects of thought. Like consciousness, it may confine itself to our own mental states; and, unlike consciousness, it may comprehend also the entire range of objective reality. In the former case it is more commonly designated by the term reflection, in the latter, observation.

Importance of Habits of Attention.—The importance of habits of attention, of the due exercise and development of this faculty of the mind, is too obvious to require special comment. The power of controlling one's own mental activity, of directing it at will into whatever channels the occasion may demand, of excluding for this purpose all other and irrelevant ideas, and concentrating the energies of the mind on the one object of thought before it, is a power of the highest value, an attainment worth any effort, and which, in the different degrees in which it is possessed, goes far to make the difference between one mind and another in the realm of thought and intellectual greatness. While the attention is divided and the mind distracted among a variety of objects, it can apprehend nothing clearly and definitely; the rays are not brought to a focus, and the mental eye, instead of a clear and well-defined image, perceives nothing but a shadowy and confused outline. The mind while in this state acts to little purpose. It is shorn of its strength.

The power of commanding the attention and concentrating the mental energy upon a given object, is, however, a power not easily acquired nor always possessed. The difficulty of the attainment is hardly less than its importance. It can be made only by earnest effort, resolute purpose, diligent culture and training. There must be strength of will to take command of the mental faculties, and make them subservient to its purpose. There must be determination to succeed, and a wise discipline and exercise of the mind with reference to the end in view. This faculty, like every other, requires education in order to its due development.

Whether certain Acts are performed without any Degree of Attention.—It is a question somewhat discussed among philosophers, whether those acts which from habit we have learned to perform with great facility, and, as we say, almost without thinking, are strictly voluntary; whether they do or do not involve an exercise of attention. Every one is aware of the facility acquired by practice in many manual and mechanical operations, as well as in those more properly intellectual. A musician sits at his instrument, scarcely conscious of what he is doing, his attention absorbed, it may be, with some engrossing topic of thought or conversation, while his fingers wander ad libitum among the keys and strike the notes of some familiar tune. Is there in such a case a special act of volition and attention preceding each movement of the fingers as they glide over the keys? And in more rapid playing, even when the attention is in general directed to the act performed, i. e., the execution of the piece, is there still a special act of attention to the production of each note as they follow each other with almost inconceivable rapidity? Dr. Stahl, Dr. Reid and others, especially many able physiologists, have answered this question in the negative, pronouncing the acts in question to be merely automatic and mechanical, and not properly involving any activity of mind. The mind, they would say, forms the general purpose to execute the given piece, but the particular movements and muscular contractions requisite to produce the individual notes, are, for the most part, involuntary, the result of habit, not of special attention or volition.

The opposite View.—On the other hand, Mr. Stewart maintains that all such acts, however easily and rapidly performed, do involve mental activity, some degree of attention, some special volition to produce them, although we may not be able to recollect those volitions afterward. The different steps of the process are, by the association of ideas, so connected, that they present themselves successively to the mind without any effort to recall them, without any hesitation or reflection on our part, and with a rapidity proportioned to our experience. The attention and the volition are instantaneous, and therefore not subsequently recollected. Still, he would say, the fact that we do not recollect them is no proof that we did not exercise them. The musician can, at will, perform the piece so slowly, as to be able to observe and recall the special act of attention to each note, and of volition to produce it. The difference in the two cases lies in the rapidity of the movement, not in the nature of the operation.

Objection to this View.—The only objection to this view, of much weight, is the extreme rapidity of mental action, which this view supposes. An accomplished speaker will pronounce, it is said, from two to four hundred words, or from one to two thousand letters in a minute, and each letter requires a distinct contraction of the muscles, many of them, indeed, several contractions. Shall we suppose then so many thousand acts of attention and volition in a minute?

Reply to this Objection.—To this it may be replied that the very objection carries with it its own answer, since if it be true that the muscles of the body move with such wonderful rapidity, it is surely not incredible that the mind should be at least equally rapid in its movements with the body. To show that both mind and body often do act with great rapidity, Mr. Stewart cites the case of the equilibrist, who balances himself on the slack rope, and at the same time balances a number of rods or balls upon his chin, his position every instant changing, according to the accidental and ever varying motions of the several objects whose equilibrium he is to preserve, which motions he must therefore constantly and closely watch. Now to do this, the closest attention, both of the eye and of the mind, to each of these instantaneous movements, is absolutely necessary, since the movements do not follow each other in any regular order, as do the notes of the musician, and cannot, therefore, by any association of ideas, be linked together, or laid up in the mind.

The Question undecided.—The question is a curious one, and with the arguments on either side, as now presented, I leave it to the reader's individual judgment and decision. Mr. Stewart is doubtless correct as to the rapidity of mental and muscular action. At the same time it seems to me there are actions, whatever may be true in the cases supposed, that are purely automatic and mechanical.

Whether we attend to more than one thing at once.—Analogous to the question already discussed, is the inquiry whether the mind ever attends or can attend to more than one thing at one and the same time; as when I read an author, my attention meanwhile being directed to some other object than the train of thought presented by the page before me, so that at the end of a paragraph or a chapter I find that I have no idea of what I have been reading, and yet I have followed with the eye, and perhaps pronounced aloud, every word and line of the entire passage. To do this must have required some attention. Have I then the power of attending to two things at once? So, when the musician carelessly strikes up a familiar air while engaged in animated conversation, and when the equilibrist balances both his own body upon the rope, and also a number of bodies upon different parts of his body, each movement of each requiring constant and instant attention, the same question arises.

Opinion of Mr. Stewart.—Mr. Stewart, in accordance with the view already expressed of the rapidity of the mind's action, maintains that we do not under any circumstances attend at one and the same time to two objects of thought, but that the mind passes with such rapidity from one to another object in the cases supposed, that we are unconscious of the transition, and seem to ourselves to be attending to both objects at once.

Illustration of this View.—An illustration of this we find in the case of vision. Only one point of the surface of any external object is at any one instant in the direct line of vision, yet so rapidly does the eye pass from point to point, that we seem to perceive at a glance the whole surface.

How it is possible to compare different Objects.—It may be asked, How is it that we are able to compare one object with another, if we are unable to bring both before the mind at once? If, while I am thinking of A, I have no longer any thought whatever of B, how is it possible ever to bring together A and B before the mind so as to compare them?

The answer I conceive to be this, that the mind passes with such rapidity from the one to the other object, as to produce the same effect that would be produced were both objects actually before it at the same instant. The transition is not usually a matter of consciousness; yet if any one will observe closely the action of his own mind in the exercise of comparison, he will detect the passing of his thoughts back and forth from one object to the other many times before the conclusion is reached, and the comparison is complete.

CHAPTER III.

CONCEPTION.

Character of this Power.—This term has been employed in various senses by different writers. It does not denote properly a distinct faculty of the mind. I conceive of a thing when I make it a distinct object of thought, when I apprehend it, when I construe it to myself as a possible thing, and as being thus and thus. This form of mental activity enters more or less into all our mental operations; it is involved in perception, memory, imagination, abstraction, judgment, reasoning, etc. For this reason it is not to be ranked as one of, and correlate with, these several specific faculties. Like the power of thought, and hardly even more limited than that, it underlies all the special faculties, and is essential to them all. Such at least is the ordinary acceptation of the term; and when we employ it to denote some specific form of mental activity, we employ it in a sense aside from its usual and established meaning.

Objects of Conception.—I conceive of an absent object of sight, as, e. g., the appearance of an absent friend, or of a foreign city, of the march of an army, or the eruption of a volcano. I conceive also of a mathematical truth, or a problem in astronomy. My conceptions are not limited to former perceptions or sensations, nor even to objects of sensible perception. They are not limited to material and sensible objects. They embrace the past and the future, the actual and the ideal, the sensible and the super-sensible.

Conceptions neither true nor false.—Our conceptions are neither true nor false, in themselves considered; they become so only when attended with some exercise of judgment or of belief. We conceive of a mountain of gold or of glass, and this simple conception has nothing to do with truth or error. When we conceive of it, however, as actually existing, and in this or that place, or when we simply judge that such a mountain is somewhere to be found, then such judgment or belief is either true or false; but it is no longer simple conception.

Not always Possibilities; nor possible Things always conceivable.—Our conceptions are not always possibilities. We can conceive of some things not within the limits of possibility. On the other hand, not every thing possible even is conceivable. Existence without beginning or end is possible, but it is not in the power of the human mind, strictly speaking, to conceive of such a thing. I know that Deity thus exists. I understand what is meant by such a proposition, and I believe it. But I cannot construe it to myself as a definite intellection, an apprehension, as I can conceive of the existence of a city or a continent, or of the truth of a mathematical proposition.

The same may be said of the ideas of the infinite and the absolute. They are not properly within the limits of thought, of apprehension, to the human mind. Thought in its very nature imposes a limitation on the object which is thought of—fathoms it—passes around it with its measuring line—apprehends it: only so far as this is done is the thing actually thought; only so far as it can be done is the thing really thinkable. But the infinite, the unconditioned, the absolute, in their very nature unlimited, cannot be shut up thus within the narrow lines of human thought. They are inconceivable. They are not, however, contradictory to thought. They may be true; they are true and real, though we cannot properly conceive them.

The Inconceivable becomes Impossible, when.—Not every thing then which is inconceivable is impossible, nor, on the other hand, is every thing which is impossible inconceivable. The inconceivable is impossible, at least it can be known to be so, only when it is either self-contradictory—as that a thing should be and not be at the same time—that a part is equal to the whole, etc.; or when it is contradictory of the laws of thought, as that two straight lines should enclose a space—that an event may occur without a cause—that space is not necessary to the existence of matter, or time to the succession of events. These things are unthinkable but they are more than that, contradictory of the established laws of thought; and they are impossible, because thus contradictory, and not merely because inconceivable. It is hardly true, as is sometimes affirmed, and as Dr. Wayland has stated, that our conceptions are the limits of possibility.

Mr. Stewart's use of the term Conception.—Mr. Stewart has employed the term Conception in a somewhat peculiar manner, and has assigned it a definite place among the faculties of the mind. He uses it to denote "that power of the mind which enables it to form a notion of an absent object of perception, or of a sensation which we have formerly felt." It is the office of this faculty "to present us with an exact transcript of what we have felt or perceived." In this respect it differs from imagination, which gives not an exact transcript, but one more or less altered or modified, combining our conceptions so as to form new results. It differs from memory in that it involves no idea of time, no recognition of the thing conceived, as a thing formerly perceived.

Objection to this use.—This use of the term is, on some accounts, objectionable. It is certainly not the ordinary sense of the word, but a departure from established usage. It is an arbitrary limitation of a word to denote a part only instead of the whole of that which it properly signifies There is no reason, in the nature of the case, why the notion we form of an absent object of perception, or of a sensation, should be called a conception, rather than our notion of an abstract truth, a proposition in morals, or a mathematical problem. I am not aware that any special importance attaches to the former more than to the latter class of conceptions. Indeed, Sir W. Hamilton limits the term to the latter. But this again is not in accordance with established usage.

INTELLECTUAL FACULTIES

PART FIRST

THE
PRESENTATIVE POWER

SENSE OR PERCEPTION BY THE SENSES.

§ I.—General Observations.

This Faculty the Foundation of our Knowledge.—Of the cognitive powers of the mind, the first to be noticed, according to the analysis and distribution already given, is the Presentative Power—the power of cognizing external objects through the senses. This claims our first attention, inasmuch as it lies, chronologically at least, at the foundation of all our cognitive powers, and in truth, of our entire mental activity. We can, perhaps, conceive of a being so constituted as to be independent of sense, and yet possess mental activity; and we can even conceive such a mind as taking cognizance, in some mysterious way, of objects external to itself. But not such a being is man—not such the nature of the human mind. Its activity is first awakened through sense; from sense it derives its knowledge of the external world, of whatever lies without and beyond the charmed circle of self; and whether all our knowledge is, strictly speaking, derived from sense, or not—a question so much disputed, and which we will not here stay to discuss—there can be no doubt that the activity of sense, and the knowledge thus acquired, is at least the beginning and foundation of all our mental acquisitions. We are constantly receiving impressions from without through the senses. In this way the mind is first awakened to activity, and from this source we derive our knowledge of the external world.

General Character of this Faculty.—In its general character the faculty now under consideration, as the name indicates, is presentative and intuitive. It presents rather than represents objects, and what the mind thus perceives it perceives intuitively, rather than as the result of reflection. The knowledge which it gives is immediate knowledge, the knowledge of that which is now and here present, in time and space.

Involves a twofold Element.—Looking more closely at the character of this faculty, we find it to involve a twofold element, which we cannot better indicate than by the terms subjective and objective. There is, in the first place, the knowledge or consciousness of our own sentient organism as affected, and there is also the knowledge of something external to, and independent of the mind itself, or the me, as the producing cause of this affection of the organism. We know, by one and the same act, ourselves as affected, and the existence and presence of an external something affecting us. This presupposes, of course, the distinct independent existence of the me and the not-me—of ourselves as thinking and sentient beings, and of objects external to ourselves, and material,—a distinction which lies at the foundation of all sense-perception. All perception by the senses involves, and presupposes, the existence of a sentient being capable of perceiving, and of an object capable of being perceived. It supposes, also, such a relation between the two, that the former is affected by the presence of the latter. From this results perception in its twofold aspect, or the knowledge, on the part of the sentient mind, at once of itself as affected, and of the object as affecting it. According as one or the other of these elements is more directly the object of attention, so the subjective and the objective character predominate in the act of perception. If the former, then we think chiefly of the me as affected, and are scarcely conscious of the external object as the source or the producing cause; if the latter, the reverse is true.

§ II—Analysis of the Perceptive Process.

Simple Sensation.—The nature of the presentative power may be better understood by observing closely the different steps of the process. As we come into contact with the external world, the first thing of which we are conscious, the first step in the process of cognition, is doubtless simple sensation. Something touches me, my bodily organism is thereby affected, and I am conscious, at once, of a certain feeling or sensation. I do not know as yet what has produced the sensation, or whether any thing produced it. I do not as yet recognize it as the result of an affection of the bodily organism, or even as pertaining to that organism in distinction from the spiritual principle. I am conscious only of a certain feeling. This is simple sensation—a purely subjective process.

Recognition of it as such.—We do not, however, stop here. The mind is at once aroused by the occurrence of the phenomenon supposed, the attention is directed to it. I cognize it as sensation, as feeling. If it be not the first instance of the kind in my experience, I distinguish it from other sensations which I have felt.

Distribution of it to the Parts affected.—More than this; I am conscious not only of the given sensation, but of its being an affection of my bodily organism, and of this or that part of the organism; I distinguish the body as the seat of the sensation, and this or that part of the body as the part affected. The organism as thus affected becomes itself an object of thought as distinct from the thinking mind that animates and pervades it. It becomes to me an externality, having extension and parts out of and distinct from each other. As thus viewed, and brought now for the first time under the eye of consciousness, it becomes known to me as the non-ego, still connected, however, by sensation with the ego, the sentient principle and as thus viewed, I become aware that the sensation which I feel is an affection of that organism, and of a certain portion of it, as the hand, or the foot. This cognizance of the sensation as such, as pertaining to the organism, and to this or that part of the same, and the consequent cognizance of the organism as such, as distinct from the sentient mind, and as thus and thus affected, is no longer simple sensation, it is perception.

Cognition of something external to the Organism itself.—This is the most simple form of immediate perception. The process does not, however, necessarily stop here. I am conscious not only of this or that part of my organism as affected, but of something external to the organism itself, in contact with and affecting it. This organism with which I find myself connected, the seat of sensation, the object of perception, is capable of self-movement in obedience to my volitions. I am conscious of the effort to move my person, and conscious also of being resisted in those movements by something external in contact with my organism. This yet unknown something becomes now the object of attention and perception—this new phenomenon—resistance, something resisting. To perceive that I am resisted, is to perceive that something resists, and to perceive this is to perceive the object itself which offers such resistance. I may not know every thing pertaining to it, what sort of thing it may be, but I know this respecting it, that it exists, that it is external to my organism, that it resists my movements. Thus the outer world becomes directly an object of perception—passes under the immediate eye of consciousness.

In what Sense these several Steps distinct.—In the preceding analysis, in order more clearly to illustrate the nature of the process, we have regarded the act of perception as broken into several distinct parts, or steps of progress. This, however, is not strictly correct as regards the psychology of the matter. Logically, we may distinguish the simple sensation as mere feeling, from the reference of the same to this or that part of the bodily organism as affected, and each of these again, from the cognizance of the external object, which by contact or resistance produces the sensation. Chronologically, the act is one and indivisible. The sensation and the perception are synchronous. We cannot separate the act of sense-perception into the consciousness of a sensation, the consciousness of the bodily organism as affected by that sensation, and the consciousness of an external something as the proximate cause of that affection. To experience a sensation, is to experience it as here or there in the sentient organism, and to perceive contact or resistance, is to perceive something in contact or resisting. There may, however, be sensation without cognizance of the external producing cause.

Restricted Sense of the term Perception.—According to the view now advanced, perception is immediate; not a matter of inference, not a roundabout reflective process. It is a cognizance direct and intuitive of the bodily organization as thus and thus affected, and of an external something in correlation with it, affecting and limiting that organism in its movements.

Usually, however, a wider range has been given to the term, and the faculty thereby denoted. It has been made to comprehend any mental process by which we refer a specific sensation to something external as its producing cause. It is thus employed by Reid and Stewart, and such has been in fact the prevalent use of the term. According to this, when we experience the sensation of fragrance, and refer that sensation to the presence of a rose, or the sensation of sound, and refer it to the stroke of a bell, or a passing carriage, we exercise the faculty of perception. Evidently, however, our knowledge in these cases is merely a matter of inference, of judgment, not of immediate direct perception, not in fact of perception at all. All that we properly perceive in such a case, all that we are directly conscious of is the fragrance or the sound. That these are produced by the rose and the bell is not perceived, but only conceived, inferred—known, if at all, only by the aid of previous experience.

Sensation as distinguished from Perception.—According to the view now presented, sensation, as distinguished from perception, is the simple feeling which results from a certain affection of the organism. It is known to us merely as feeling. Perception takes cognizance of the feeling as an affection of the organism, and also of the organism as thus affected, and consequently as external to the me, extended, having parts, etc. It apprehends also objects external to the organism itself limiting and affecting its movements. Sensation is the indispensable condition of perception. If there were no sensation, there would be no perception. The one does not precede, however, and the other follow in order of time, but the one being given, the other is given along with it. The two do not, however, coexist in equal strength, but in the relation, as stated by Hamilton, of inverse ratio; that is, beyond a certain point, the stronger the sensation, the weaker the perception, and vice versâ.

Sensation as an Affection of the Mind.—It has been common to speak of sensation as lying wholly in the mind. Primarily, however, it is an affection of the nervous organism, and through that organism, as thus affected, an impression is made on the mind. If it were not for the mind present with the organism, and susceptible of impression from it, and thus cognizant of changes in it, the same changes might be produced in the organism as now, but we should be entirely unconscious of and insensible to them. In certain states of the system this actually happens, as in sound sleep, the magnetic state, the state produced by certain medicinal agents as ether, chloroform, opium, and the intoxicating drugs of the East. In those cases, the connection between the mind and the nervous organism seems to be in some manner interrupted or suspended, and consequently there is for the time no sensation. The nerves may be irritated, divided even, and still no pain is felt.

It is not true, however, that the sensation is wholly in the mind. It is in the living animated organism, as pervaded by the mind or spiritual principle, mysteriously present in every part of that organism, and cognizant of its changes; and neither the body alone, nor the mind alone, can be said to possess this faculty, but the two united in that complex mysterious unity which constitutes our present being.

§ III.—Analysis and Classification of the Qualities of Bodies.

Difference of Qualities.—The qualities of bodies as known to us through sensation and perception are many and various. On examination, a difference strikes us as existing among these qualities, which admits of being made the basis of classification. Some of them are qualities which strike us at once as essential to the very existence of matter, at least in our notion of it, so that we cannot in thought divest it of these qualities, and still retain our conception of matter. Others are not of this nature. Extension, divisibility, size, figure, situation, and some others, are of the former class. If matter exists at all, it must, according to our own conceptions, possess these qualities. We cannot think them away from it, and leave matter still existing. But we can conceive of matter as destitute of color, flavor, savor, heat, cold, weight, sound, hardness, etc. These are contingent and accidental properties not necessary to its existence.

How named and distinguished.—Philosophers have called the former class primary, the latter secondary qualities. The former are known à priori, the latter by experience. The former are known as qualities, in themselves, the latter only through the affections of our senses.

The primary qualities then have these characteristics:

1. They are essential to the very existence of matter, at least in our conception.

2. They are to be known à priori.

3. They are known as such, or in themselves.

The secondary, on the contrary, are:

1. Accidental, not essential to the notion of matter.

2. To be known only by experience.

3. To be learned only through the affection of the senses.

Further Division of secondary Qualities.—A further division, however, is capable of being made. The secondary qualities, as now defined, comprise, in reality, two classes. There are some, which, while known to us only through the senses, have still an existence as qualities of external objects, independent of our senses. As such they are objects of direct perception. Others, again, are known, not as qualities of bodies, but only as affections of sense, not as objective, but only as subjective, not as perceptions, but only as sensations. Thus I distinguish the smell, the taste, and the color of an orange. What I distinguish, however, is after all only certain sensations, certain affections of my own organism. What may be the peculiar properties or qualities in the object itself which are the exciting cause of these sensations in me, I know not. My perception does not extend to them at all. It is quite otherwise with the qualities of weight, hardness, compressibility, fluidity, elasticity, and others of that class. They are objects of perception, and not of sensation merely.

These Classes, how distinguished.—The class first named, are qualities of bodies as related to other bodies. The other class are qualities of bodies as related only to our nervous organization. The former all relate to bodies as occupying and moving in space, and come under the category of resistance. The latter relate to bodies only as capable of producing certain sensations in us. We may call the former mechanical, the latter physiological.

Connection of Sensation with the external Object.—From long habit of connecting the sensation with the external body which produces it, we find it difficult to persuade ourselves that taste and smell are mere affections of our senses, or that color is really and simply an affection of the optic nerve of the beholder, and that what is actually perceived in these instances is not properly a quality of the external object. A little reflection, however, will convince us that all which comes to our knowledge in these cases, all that we are properly cognizant of, is the affection of our own nervous organism, and that whatever may be the nature of the qualities in the object which are the producing cause of these sensations in us, they are to us occult and wholly unknown.

Power of producing these Sensations.—It is not to be denied, of course, that there is in external objects the power of producing these sensations in us, under given circumstances; but to what that power is owing, in what peculiarity of constitution or condition it consists, we know not. We have but one name, moreover, for the power of producing, and the effect produced. Thus the color, taste, smell, etc., of an object may denote either the sensation in us, or the unknown property of matter by virtue of which the sensation is awakened. It is only in the sense last mentioned, that the qualities under consideration may properly be called qualities of bodies.

Enumeration of the several Qualities as now classed.—According to the classification now made, the qualities of bodies may be thus enumerated.

I. Primary.—Extension, divisibility, size, density, figure, absolute incompressibility, mobility, situation.

II. Secondary.—A. Objective, or mechanical—as heavy or light, hard or soft, firm or fluid, rough or smooth, compressible or incompressible, resilient or irresilient, and any other qualities of this general nature resulting from attraction, repulsion, etc.

B. Subjective or physiological—as color, sound, flavor, savor, temperature, tactual sensation, and certain other affections of the senses of this nature.

§ IV.—Organs of Sense.—Analysis of their Several Functions

Number of the Senses.—The different senses are usually reckoned as five in number. They may all be regarded, however, as modifications of one general sense, that of touch—or, in other words, the susceptibility of the nervous system to be excited by foreign substances brought into contact with it. This is the essential condition of sensation in any case, and the several senses, so called, are but so many variations in the mode of manifesting this excitability. There is a reason, nevertheless, for assigning five of these modifications and no more, and that is, that the anatomical structure indicates either a distinct organ, as the ear, the eye, etc., or at least a distinct branch of the nervous apparatus, as in the case of smell and taste, while the whole nervous expansion as spread out over the surface of the body contributes to the general sense of touch.

The Senses related to each other.—Distinct Office of each.—It is evident enough that these several senses sustain a certain relation to each other. They are so many and no more, not merely by accident; not merely because so many could find room in the bodily organization; not merely because it might be convenient to have so many. Let us look at the office performed by each, and we shall see that while each has its distinct function, not interchangeable with that of any other, it is a function more or less necessary to the animal economy. Remembering that the design and use of the several senses is to put us in possession of data, by means of which, directly or indirectly, we may gain correct knowledge of the external world, let us suppose the inquiry to be raised, What senses ought man to have for this purpose? What does he need, the material universe remaining what it is?

Function of the Sense of Touch.—Things exist about us in space, having certain properties and relations. We need a sense then, first and chiefly, that shall acquaint us with objects thus existing, taking cognizance of what lies immediately about us in space. This we have in the general sense of touch, making us acquainted with certain objective or mechanical qualities of external objects.

This Sense, how limited.—This, however, avails only for objects within a short distance, and capable of being brought into contact. It operates also synthetically and slowly, part after part of the object being given as we are brought into contact with different portions of it successively until the process is so far complete that, from the ensemble of these different parts, our understanding can construct the whole.

Possibility of a Sense that shall meet these Limitations.—We can conceive of a sense that should differ in both these respects—that should take cognizance of distant objects, not capable perhaps of being brought into contact—and that should also operate analytically, or work from a given whole to the parts, and not from the parts to a whole, thus giving us possession at once of a complete object or series of objects. Such a sense, it is easy to see, would possess decided advantages, and in connection with the one already considered, would seem to bring within the sphere of our cognizance almost the complete range of external nature. This we have, and this exactly, in the sense of vision. It takes in objects at a distance, and takes in the whole at a glance.

This new Sense still limited.—This new sense, however convenient and useful as it is, has evidently its limitations. It is available only through a given medium, the light. Strictly speaking, it is the light only that we see, and not the distant object; that is known indirectly by means of the light that variously modified, travels from it to the eye. When this fails, as it does during several hours of the twenty-four, or when it is intercepted by objects coming between and shutting out the forms on which the eye seeks in vain to rest, then our knowledge from this source is cut off.

Still another Sense desirable.—Under these circumstances, might it not be well, were there given an additional sense, of the same general nature and design, but operating through a different medium, sure to be present wherever animal life exists, so that even in the darkness of the night, or the gloom of the dungeon, we might still have means of knowing something of the surrounding objects. And what of this medium, or avenue of sense, were of such a nature as to be capable of modification, and control, to some extent, on our part, and at our pleasure, so as to form a means of voluntary communication with our fellow-beings. Would not such an arrangement be of great service? Exactly these things are wanted; exactly these wants are met, and these objects accomplished, by a new sense answering to these conditions—the sense of hearing—the cognizance of sound. This we produce when we please by the spoken word, the vocal utterance, whether of speech, or musical note, or inarticulate cry, varied as we please, high, low, loud, soft—a complete alphabet of expression, conveying thus by signals, at once rapid and significant, the varying moods and phases of our inner life to other beings that had else been strangers, for the most part, to the thoughts and feelings which agitate our bosoms.

Senses for another Class of Qualities.—The senses, as thus far analyzed, have reference primarily to the number magnitude, and distance of objects as occupying space—to quantities rather than qualities. Were it possible now to add to these a sense, or senses that should take cognizance of quality, as well as existence and quantity—that should detect, to some extent at least, the chemical properties of bodies as connected especially with the functions of respiration and nutrition—the list of senses would seem to be complete. This addition is made, this knowledge given, in the senses of smell and taste.

Possibility of additional Senses.—To those already named, other senses might doubtless have been added by the Creator, which would have revealed, it may be, properties of matter of which we have now no conception. It is not to be supposed that we know every thing respecting the nature and qualities of even the most familiar and common objects. Many things there may be, actual, real, in the world about us, of which we know nothing, because they come not within the range of any of our senses. But all that is essential to life, and happiness, and highest welfare is doubtless imparted by the present arrangement; and when closely studied, no one of these senses will be found superfluous, no one overlapping the province of another, but working each its specific end, and all in harmony.

The proper Office of Psychology in respect to the Senses.—It is the province of the anatomist and the physiologist to explain the mechanical structure of the several organs of sense, and their value as parts of the physical system. The psychologist has to do with them only as instruments of the mind, and it is for him to show their connection and proper office as such. This has been attempted in the preceding analysis.

The kind of Knowledge afforded by the Senses.—It is to be noticed, in addition, that with the exception of the tactual sense, and possibly of sight, these senses give us no direct, immediate knowledge of external things. They simply furnish data, signs, intimations, by the help of which the understanding forms its conclusions of the world with out. They are the receiving agents of the mind. This is, in fact, the chief office of sense, to receive through its various avenues the materials from which the understanding shall frame conceptions of things without; to convey, as it were, a series of telegraphic despatches along those curious and slender filaments that compose the nervous organization, by means of which the soul, keeping her hidden seat and chamber within, may receive communication from the distant provinces of her empire. These signs the understanding interprets; and in so far as this is the true nature of the process, it is not a process of immediate and proper perception. I hear, for example, a noise. All that I really perceive in this case is the sensation of sound. I refer it, however, to an external cause, to a carriage passing in the street. I specify, moreover, the kind of carriage, perhaps a coach, or a wagon with iron axles. I have observed, have learned by experience, that sounds of this nature are produced in this way, that is, by carriages passing, and by such carriages. Hence I judge that the sound which I now hear is produced in the same way. It is an inference, a conception merely. All that sense does is to receive and transmit the sign, which the understanding interprets by the aid of former experience. And the same is true of the other senses, with the exceptions named.

Not therefore of little Value.—We are not to infer, however, that these senses are on this account of no special value or importance to us. They do precisely what is needed. They put us in possession of just the data wanted in order to the necessary information concerning external things. It is only the theorist who undervalues the senses, and he only in his closet. No man, in the full possession of his reason, and his right mind, can go forth into this fair and goodly world, and not thank God for every one of those senses—sight, hearing, taste, touch, and smell. Their true and full value, however, we never learn till we come to be deprived of their use; till with Milton we exclaim,

"Seasons return; but not to me returns
Day, or the sweet approach of even or morn."

§ V.—Amount of Information Derived from the Respective Senses

A further Question as to one Class of the Senses.—The relations and specific functions of the several senses have been already described. Some further questions arise, however, respecting the precise amount and kind of information afforded by that class of the senses which; as we have seen, relates to the spatial properties of bodies, in distinction from the chemical, viz.: hearing, sight, and touch.

What is given in Hearing.—And first, as to the sense of hearing. What is it precisely that we hear? When we listen to a sound, we speak of hearing the object that produces the sound; we say, I hear a bell, a bird, a gun, etc. Strictly speaking, we do not hear the object, but only the sound. It is not the bell or the bird that we hear, but the vibration of the air produced by bell and bird. This has been already illustrated by reference to a carriage passing in the street. It is only by experience, aided by other senses, that we learn to refer the sound to its producing cause.

Hearing not properly Perception.—Is hearing then a sensation merely, or is it a perception? If by perception we mean a direct knowledge of the external object—which is the proper sense of the word—hearing certainly is not perception. It gives us no such immediate knowledge. What we perceive in hearing is merely the sensation of sound. It may be doubted whether by this sense alone we should ever get the idea that what we hear is any thing external to ourselves.

Affords the means of Judging.—As it is, however, we judge, not only of the existence and nature, but of the distance and direction of the external object whence the sound proceeds. We learn to do this with great correctness, and with great facility. No sooner do we hear a sound, in most instances, than we form an opinion at once, from what direction it comes, and what produces it; nor are we often mistaken in our judgment. The faculty of judging by the ear as to the direction of the sound, and the nature of the object producing it, may be cultivated by care and practice to a remarkable degree of accuracy. Napoleon was seldom mistaken as to the direction and distance of a cannonade. It is said that the Indian of the north-western prairies by applying his ear to the ground, will detect the approach of a body of cavalry at a distance beyond the reach of vision, and distinguish their tread from that of a herd of buffaloes.

Number of Sounds.—The number of sounds which the ear can distinguish is almost without limit. There are, it is said, five hundred distinct tones which an ear of usual accuracy can recognize, and each of these tones admits of five hundred variations of loudness, giving, in all, two hundred and fifty thousand different sounds.

Power of Sound over the Mind.—The power of sound to affect the mind, and especially the feelings, is too well known to require specific statement. The note of an instrument, the tone of a human voice, the wild warbling of a bird, the tinkling of a bell, the variations of speech and of song, from the high and shrill to the low and heavy intonation, from the quick and impetuous to the slow and plaintive movement, these simple varieties of tone affect powerfully the heart, and find their way at once and irresistibly to the feelings. Hence the power of music over even the uncultivated mind; hence too in no small degree the power of the skilful orator over the feelings of his audience. It is not merely, nor so much, the thing said, in many cases, as the way of saying it, that touches and sways the assembled multitude. Tones and sounds have a natural meaning. They are the natural language of the heart. They express emotion, and hence awaken emotions in others.

The Question as to Sight.—Turning now from the sense of hearing to that of sight, the question arises, What is it precisely that we perceive by the eye? When we fix the eye upon any object, more or less remote, what is it, strictly speaking, that we see, extension and figure, or only color? Is it by vision that we learn primarily the distance of objects and their locality? These are points requiring investigation.

Does Sight give Extension and Figure.—As to the first of these questions, whether extension and figure are objects of direct visual perception. No doubt they are associated in our minds with the act of vision, so that the moment we see an object we obtain an idea of it as extended, and of such and such dimensions and figure. The question is, whether it is really through the sense of sight that we obtain this idea, or in some other way. Had we no other means of information, would sight alone give us this? When we first open our eyes on external objects, do we receive the idea of extension and figure, or only of color? The fact that as matters are, we cannot in our experience separate the notion of some surface extension from the sensation of color, is not decisive of these questions. We cannot, as Dr. Brown observes, separate the color from the convexity and magnitude of an oak before us, but this does not prove that convexity and magnitude are objects of immediate and original perception. If every surface in nature had been convex, suggests the same writer, we should probably have found the same difficulty in attempting to conceive of color as separate from convexity, that we now find in attempting to conceive of it as separate from length and breadth. As it is, however, our sensation of color has not always been associated with convexity, while it has been always associated with surface extension. Hence it is, he maintains, that we seem to perceive, by the eye, the length, and breadth, and objects along with their color.

Argument from the Affection of a Portion of the Retina.—The fact that in vision a certain portion of the retina in length and breadth is actually affected by the light falling on it, has been supposed by some to be conclusive of the fact that we perceive the length and breadth of the external object by the eye. This does not necessarily follow. As Dr. Brown contends, it is equally true that a certain part of the organ of smell is affected by odors, and a certain part of the auditory nerve is affected by sounds, yet we are not conscious of any perception of extension by either of these organs; we neither smell nor hear the length, and breadth, and magnitude of objects; nor is there any reason to suppose that the particular portion of the retina affected has any thing to do with the original sensation of sight.

Amount of the preceding Arguments.—These arguments however, do not strike me as conclusive. They merely show the possibility that extension and figure may be acquired rather than original perceptions. They do not amount to positive evidence that they are so.

An Argument to the Contrary.—On the other hand, there is one consideration of a positive character, which to most minds will be likely to outweigh the merely negative arguments already adduced. Color is a property of light, and light comes to us reflected from objects occupying space; we perceive it only as we perceive it spread over and reflected from some surface. Extension, then, surface expansion of the reflecting object, is the indispensable condition of the visibility of light itself, and so of color, as reflected from the object. Now it is difficult to persuade ourselves that what we know to be an essential condition of the perception of color, and what we seem to perceive along with the color, and cannot, even in thought, wholly separate from it, is not, after all, really perceived by the eye.

Argument from recent Discoveries.—Indeed, recent discoveries in science seem to vindicate that not only surface extension, but trinal extension, or solidity, may be an object of direct perception by the eye. I refer to the researches of Wheatstone, in binocular vision, which go to show, that in consequence of the difference of the images formed upon the right and the left eye, as occupying different positions with reference to the object seen, we are enabled by the eye to cognize the solidity as well as the extension of objects. The difference of figure in the two images gives us this. That such is the case is shown by an instrument, the stereoscope, so constructed as to present separately the image as formed on each eye, which, when separately viewed, appear as mere plane surfaces, but when viewed together, the right image with the right eye, and the left one with the left eye, at the same time, present no longer the appearance of plane surfaces, but the two images combine to form one distinct figure, and that a solid, having length, breadth, thickness, and standing out with all the semblance of the real object.

It is hardly necessary to say that if extension is an object of perception by the eye, so also is figure, which is merely the limitation of extension in different directions.

Second Question—Does Sight give Distance?—Is it also by vision that we obtain the idea of the distance of objects and their externality? Does vision alone give the idea that what we see is numerically distinct from ourselves, and that it occupies this or that particular locality? So it would seem, judging from the impression left upon the mind in the act of vision. We seem to see the object as here or there, external, more or less distant in space. We distinguish it from ourselves.

The negative View.—This is denied by some. All that we see, they contend, is merely the light coming from the object, and from the variations and modifications which this exhibits we learn to judge by experience of the distance and locality of the object. It is a matter of judgment and not of perception. We have learned to associate the two things, the visual appearance and the distance.

Argument in the Negative.—In proof of this they adduce the fact that we are frequently mistaken in our estimate of the distance of objects. If there be more or fewer intervening objects than usual, if the atmosphere be more or less clear than usual, or any like circumstance affords a variation from our ordinary experience, we are misled as to the distance of the object. Hence we mistake the distance of ships at sea, or of objects on a prairie or a desert, the width of rivers, the height of steeples, towers, etc.

Further Argument in the Negative.—It is further contended that facts show that the impressions of sight alone, uncorrected by experience, do not convey the idea of distance at all, but that what we see seems to be in connection with the eye itself, until we learn the contrary by the aid of other senses. This, it is said, is the experience of persons who have been operated upon for cataract, particularly of a patient whose case is described by Cheselden, and who thought every thing which he saw, touched his eyes. It is said also to have been the same with Caspar Hauser, when first liberated from the long confinement of his dungeon, and permitted to look out upon the external world. The goodly landscape seemed to him to be a group of figures, drawn upon the window.

Force of this Argument.—This, however, is not inconsistent with the perception of externality by vision, since even what seems to be in contact with the eye, nay, what is known to be so, may still be known as external. Contact implies externality. It is very much to be doubted, moreover, whether the cases now referred to, coincide with the usual experience of those who are learning to see. The little child seems to recognize the externality and remoteness from his own person of the objects which attract his attention, as soon as he learns to observe surrounding objects at all, and, though he may not judge correctly of their relative distance from himself, never seems by his movements to suppose that they are in contact with his eye or with any part of his person. The young of animals, also, as soon as they are born, seem to perceive by the eye, the externality, the direction, and the distance of objects, and govern their movements accordingly. It is not, in these cases, a matter of experience, but of direct perception. These facts render it doubtful, to say the least, whether the common impression—that which in spite of all arguments to the contrary, is, and always will be made upon the mind in the act of vision, viz., that we see objects as external, as having locality, and as more or less remote from us—is not, after all, the correct impression.

Learning to judge of Distance not inconsistent with this View.—- Nor does it conflict with this view that we learn to judge of the true distance of objects, and are often deceived in regard to it. The measurement of distance, the more or less of it, is of course a matter of experience, a thing to be learned by practice. It does not follow, however, that we may not by the eye directly, and at first, perceive an object to be external, and removed from us, in other words distant, though we may not know at first how distant. The rays of light that come to us from this external object, may give us direct perception of the object as external, as extended, and as occupying apparently a given locality in space more or less remote, while at the same time it may be left to other senses and to experience to determine how great that distance is.

Questions as to Touch.—Passing now from the sense of sight to that of touch, we find similar questions discussed among philosophers respecting the precise information afforded by this sense. Does touch give us immediate perception of externality, extension, form, hardness, softness, etc., including the various mechanical properties of bodies? To this sense it has been common to ascribe these faculties of perception. They are so attributed by Reid, Upham, Wayland, and, I believe, by modern writers generally, with the exception of Brown and Hamilton.

Probability of another Source of Information.—It may be questioned, I think, whether, as regards some of these qualities at least, it is not rather the consciousness of resistance to muscular effort, than the sense of touch, properly speaking, that is the informing source. So, for example, as to hardness; the application of an external body lightly to the hand awakens the sense of touch, but conveys no idea of hardness. Let the same object be allowed to rest with gradually increasing weight upon the hand until it becomes painful, and we get the idea of weight, gravitation, but not of the hardness or impenetrability of the object. It is only when our muscular effort to move or penetrate the external body is met and resisted by the same, that we learn the impenetrability of the opposing body.

Other Perceptions attributable to the same Source.—So with regard to externality, extension, and form. When an external object, a cube, for example, or an ivory ball, is placed on the palm of the hand, sensation is awakened, but is that sensation necessarily accompanied with the perception of the external object as such? Does the mere tactual sensation, in the first instance, and of itself, inform us that there is something external to ourselves, that what we feel is not a part of our own organism? We are conscious of a change in the sensation of the part affected, but are we immediately conscious that this change is produced by something external? Let there be given, however, the consciousness of resistance to our muscular movements, as when the cube or ball, for instance, prevents the effort to close the hand, or when our locomotion is impeded by the presence of some obstacle, and will not the same resistance inform us of the extension of the resisting body, and so of its form and figure? We learn whereabout in space this resistance occurs, and where it ceases. The tactual sensation would indeed very soon come to our aid in this cognition, and serve as a guiding sense, even in the absence of the former. The question is, whether this alone would, in the first instance, give us such cognitions?

Our first Ideas of Extension, how derived.—We have had reference in this discussion only to the qualities of external bodies. There can be little question that our first ideas of extension are derived from our own sentient organism, the consciousness of sensations in different parts of the body, distinct from, and out of each other, thus affording the knowledge of an extended sentient organization. The idea of externality, or outness, and extension, thus acquired, the transition is easy from the perception of our own bodies as possessing these qualities, to the cognizance of the same qualities in external objects.

§ VI.—Credibility of our Sensations and Perceptions.

Denied by some.—There have always been those who were disposed to call in question the testimony of the senses. Such were the Eleatics and the Skeptics among the Greek philosophers, and there have not been wanting among the moderns minds of acuteness and ingenuity that have followed in the same path. While admitting the phenomena of sense, the appearance of things as being so and so, they have called in question the corresponding objective reality. Things appear to me to be thus and thus—such and such impressions are made on my senses—that I cannot deny; but how do I know that the reality corresponds to my impressions, or, in fact, that there is any reality? How know we our senses to be reliable? What evidence have we that they do not habitually deceive us?

Evidence demanded.—It were perhaps a sufficient answer to this question to reply, What evidence have we, or can we have, that they do deceive us? In the absence of all evidence to the contrary, is it not more reasonable to suppose that our perceptions correspond to realities, than that they are without foundation, uncaused, or caused by something not at all answering to the apparent object of perception; more reasonable to suppose that there is a real table or book answering to my perception of one, than that I have the perception while there is no such reality? It remains with those, then, who question and deny the validity of sense-perception, to show reasons for such denial. And this becomes the more imperative on them, inasmuch as they contradict the common belief and universal opinion of mankind—nay, what, in spite of all their arguments, is still, by their own confession, their own practical conviction and belief.

Evidence impossible.—But whence is this evidence to come? Where is it to be sought? How are we to prove that sense deceives us, except by arguments drawn from sense? And if sense is not reliable in the first instance, why rely upon it in the second, to prove that it is not reliable? If the senses do habitually deceive us, manifestly it can never be shown that they do. And, even if this could be shown, it would be impossible to find any thing better to rely upon in their stead. We have these guides or none. We have these instruments of observation provided for the voyage of life. We may pronounce them worthless and throw them into the sea, but we cannot replace them.

Inconsistent and contradictory Testimony of Sense.—But it may be replied that the testimony of sense is often inconsistent with itself, and contradictory of itself. What is sweet to one is sour and bitter to another. What seems a round tower in the distance becomes a square one as you approach; and the straight stick that you hold in your hand appears crooked when thrust into the water. There is in reality, however, no contradiction or inconsistency in the cases supposed. The change of circumstances accounts in every instance for the change of appearance. In the case of the stick, for example, the different density of the water accounts for the refraction of the rays of light that pass through it, and this accounts for the crooked appearance of the stick that is only partially submerged. So in the other cases; it is no contradiction that an object which appears round at a distance of ten miles, should appear square at the distance of so many rods—or that the taste of two persons should not agree as to the savor of a given object.

Deceptions of Sense.—It may be further objected that in certain states of the physical organism, sensations are experienced which seem to be of external origin, but are really produced by internal changes; and that in such cases we have the same perceptions, see the same objects, hear the same things, that we should if there were a corresponding external reality, while nevertheless there is no such reality, and it can be proved that there is none. If this may happen in some cases, why not in others, or in all?

Reply.—I reply, the simple fact, that in the case supposed the deception can be detected and proved, shows the difference between that and ordinary perception. If the senses were not habitually reliable, we could not detect the mistake in this particular instance. If all coin were counterfeit, how could we detect a counterfeit coin? We know, moreover, how to account for the mistake in the case before us. It occurs, by the supposition, only in a certain state of the organism, that is, only in a diseased, abnormal condition of the system. The exception proves the rule.

Distinction of direct and indirect Testimony.—A distinction is to be made, in the discussion of this subject, between the direct and indirect testimony of the senses, between that which is strictly and properly perception, and that which is only conception, judgment, inference. What I really perceive, for example, in the case of the distant tower, or the stick partially under water, is only a given appearance; I infer from that appearance that the tower is round and the stick crooked, and in that inference I am mistaken. My judgment is at fault here, and not my senses. They testified truly and correctly. They gave the real appearance, and this was all they could give, all they ever give. This has been well stated by Dr. Reid, and, long before him, the same ground was taken, in reply to the same objection, by Aristotle and also by Epicurus.

Direct Perception gives what.—In regard to direct and immediate perception, the case is different. Here the testimony is positive to the existence of the object. When something resists my voluntary movement, I am conscious of that resistance, conscious of something external and resisting. I cannot deny the fact of that consciousness. I may, however, deny the correctness, the truthfulness of what consciousness affirms. To do this, however, is to put an end to all reasoning on the subject, for, when we give up consciousness as no longer reliable, there is nothing left to fall back upon. If any one chooses to leap from this precipice, we can only say finis.

§ VII.—HISTORICAL SKETCH.

I. Of Different Divisions of the Qualities of Bodies.

The Greek Philosophers.—The distinction of the qualities of bodies into two classes, differing in important respects, is by no means a modern one. It was recognized by some of the earlier Greek philosophers, who held that the sweet, bitter, hot, cold, etc., are rather affections of our own senses than proper qualities of matter, having independent existence. Subsequently the view was adopted by Protagoras, and by the Cyrenean and Epicurean schools. Plato held it, and especially and very fully, Aristotle, who calls the qualities to which we have referred, and which are usually denominated secondary, affective qualities, because they have the power of affecting the senses, while the qualities now usually termed primary, as extension, figure, motion, number, etc., he regards as not properly objects of sense. The former class he calls proper sensibles, the latter, common.

The Schoolmen.—The schoolmen made much of this distinction, and held, with Aristotle, that the qualities now called primary, require, for their cognition, other faculties than those of sense.

Doctrine of Galileo.—Galileo points out the true ground and philosophy of this distinction, and also gives the name primary to the class referred to, viz., those qualities which are necessary to our conception of body, as for example, figure, size, place, etc., while, on the contrary, colors, tastes, etc., are not inherent in bodies, but only in us, and we can conceive of body without them. The former are real qualities of bodies, while the latter are only conceptions which give us no real knowledge of any thing external, but only of the affections of our own minds.

The Moderns.—Descartes and Locke merely adopted these distinctions as they found them, without essential modification. So also did Reid and Stewart, although both included among the primary qualities some which are properly secondary, as roughness, smoothness, hardness, softness. Indeed Stewart restricted the primary qualities to those and such as those just named.

Hamilton.—No writer has so fully elaborated this matter as Sir William Hamilton, to whom we are indebted mainly for the historical facts now stated, and whose dissertations are and must ever remain an invaluable thesaurus on the philosophy of perception. So complete and elaborate is his classification of the qualities of matter, that I shall be pardoned for giving a synopsis of its principal points in this connection.

Hamilton's Scheme—General Divisions.—He divides the qualities of bodies into three classes, which he calls primary, secundo-primary, and secondary. The primary are thought as essential to the very notion of matter, and may be deduced à priori, the bare notion of matter being given; while the secundo-primary and the secondary, being accidental and contingent, must be deduced à posteriori, learned by experience. His deduction of the primary qualities is as follows:

Primary Qualities.—We can conceive of body only as, I. Occupying space; II. Contained in space. Space is a necessary form of thought, but we are not obliged to conceive of space as occupied, that is, to conceive of matter. When conceived it must be under the conditions now named.

I. The property of occupying space is Simple Solidity, which implies, a. Trinal extension, or length, breadth, and thickness; b. Impenetrability, or the property of not being reduced to non-extension. Trinal extension involves, 1. Number, or Divisibility; 2. Size, including Density; 3. Shape.

II. The attribute of being contained in space, affords the notion, 1. Of Mobility; 2. Of Position.

The essential and necessary constituents then of our notion of matter are, 1. Extension (comprising under it, 2. Divisibility; 3. Size; 4. Density; 5. Figure); 6. Ultimate Incompressibility; 7. Mobility; 8. Situation. These are the primary qualities, products, in a sort, of the understanding, developing themselves with rigid necessity out of the given notion of substance occupying space.

Secundo-Primary Qualities.—The secundo-primary are contingent modifications of the primary, all have relation to space, and motion in space, all are contained under the category of resistance, or pressure, all are learned or included as results of experience, all have both an objective and subjective phase, being at once qualities of matter, and also affections of our senses.

Considered as to the sources of resistance, there is, I. That of Co-attraction, under the forms of a, Gravity, b, Cohesion; II. That of Repulsion; III. Inertia; all which are capable of minute subdivision. Thus from cohesion follow the hard and soft, firm and fluid, tough and brittle, rigid and flexible, rough and smooth, etc., etc. From repulsion are derived compressible and incompressible, resilient and irresilient.

Secondary Qualities.—The secondary qualities are, as apprehended by us, not properly attributes of body at all, but only affections of our nervous organism. They belong to bodies only so far as these are furnished with the power of exciting our nervous organism to the specific action thus designated. To this class belong color, sound, flavor, savor, tactile sensation, feeling of heat, electricity, etc. Such also are titillation, sneezing, shuddering, and the various sensations, pleasurable or painful, resulting from the action of external stimuli.

These Classes further distinguished.—Of the qualities thus derived, the primary are known immediately in themselves, the secondary only mediately in their effects on us, the secundo-primary both immediately in themselves, and mediately in their effects on us. The primary are qualities of body in relation to body simply, and to our organism as such; the secundo-primary are qualities of body in relation to our organism, not as body in general, but as body of a particular sort, viz.: propelling, resisting, cohesive; the secondary are qualities of body in relation to our organism as excitable and sentient. The primary may be roundly characterized as mathematical, the secundo-primary as mechanical, the secondary as physiological.

Reasons for retaining the twofold Division.—Such, in brief outline, are the principal points of Hamilton's classification. While following in the main the distinctions here indicated, I have preferred to retain the old division into primary and secondary, as at once more simple, and sufficiently accurate, merely dividing the secondary into two classes, the mechanical (secundo-primary of Hamilton), and physiological. We are thus enabled, not merely to retain a division and nomenclature which have antiquity and authority in their favor, and are well-nigh universally received, but we avoid the almost barbarous terminology of Sir William's classification—while, at the same time, we indicate with sufficient precision the important distinction between the so-called secundo-primary and secondary qualities.

II. Of Different Theories of Perception.

Realists and Idealists.—There are two leading theories, quite distinct from each other, which have widely prevailed, and divided the thinking world, as to the philosophy of perception. The one maintains that in perception we have direct cognizance of a real external world. This is the view taken in the preceding pages, and now generally held by psychologists in this country, and to some extent in Europe But for a long period, the prevalent, and in fact, until the time of Reid in Scotland, and Kant in Germany, the almost universally-received opinion was the reverse of this—that in perception, as in any and all other mental acts, the mind is conscious only of its own ideas, cognizant of itself and its own states only, incapable, in fact, of knowing any thing external to itself. Those who hold the former view are termed Realists, the latter Idealists.

Further division of the latter.—The latter, however, are of two classes. The Absolute Idealists hold that the notion we have of external things is purely subjective, having no external counterpart, no corresponding outward reality. In distinction from this the greater part maintain that while we are cognizant, directly and strictly, of nothing beyond our own minds, nevertheless there is an external reality corresponding to the idea in our minds, and which that idea represents. Hence they have been designated Representative Idealists, or, as Sir William Hamilton terms them, Cosmothetic Idealists.

Further Distinction.—Of these latter, again, some hold the idea which we have of an external world to be merely a state or modification of the mind itself; others regard it as a sort of intermediate connecting link between mind and matter. The former may be called egoistic, and the latter non-egoistic.

Summary of Classes.—We have then these three great classes—the Natural Realists, the Absolute Idealists, and the Representative Idealists comprising the Egoistic and Non-Egoistic divisions.

Distinguished Writers of the different Classes.—On the roll of absolute idealism are names of no small distinction: Berkley and Hume, in England, Fichte and Hegel, in Germany, are of the number; while among the representative idealists one finds Descartes, Arnauld, Malebranche, Leibnitz, Locke, in fine, the greater number of philosophic writers from Descartes onward to the time of Reid. Subsequently even, we find a writer of no less repute than Dr. Brown assuming, as the basis of his philosophy of perception, the exploded theory of representative idealism, under the egoistic form. Of natural realists since the time of Reid, Sir W. Hamilton is the most distinguished.

Origin of Representative Idealism.—The doctrine of representative perception doubtless originated in the difficulty of conceiving how a purely spiritual existence, the human mind, can, by any possibility, take cognizance of, or be affected by, a purely material substance, the external world. The soul seated in its presence-chamber, the brain, can cognize nothing beyond and without, for nothing can get except where it is present. It must be, then, said the philosophers, that in order to the mind's perceiving any thing of that which lies beyond and without its own immediate locality, there must come to the mind from that outer world certain little images bearing some resemblance to the things without, and representing to the soul that external world. These images—more refined than matter, less spiritual than mind itself, of an intermediate nature between the two—they termed ideas.

Tendency of Representative to Absolute Idealism.—It is easy to see how such a doctrine would lead almost inevitably to absolute idealism. If we do not in perception take cognizance directly of matter external, but only of certain images or ideas in our own minds, then how do we know that these images correctly represent the external reality, which we have never cognized, and never shall? How do we know, in fact, that there is any such external reality? What evidence have we, in a word, of the existence of any thing beyond and without our own minds? This was the actual result to which Berkley and Hume drove the then prevalent philosophy of Europe, as to a legitimate and inevitable result.

Relation of Dr. Reid to this Controversy.—To Dr. Reid belongs the credit of rescuing philosophy from this dangerous extreme, by showing the utter falsity of the ideal theory. He took the ground that the existence of any such representative images in the mind is wholly without proof, nay more, is inconceivable; that while we can conceive of an image of form or figure, we cannot conceive of an image of sound, or of taste or smell. The hypothesis is wholly without foundation. But even if it were conceivable and established by sufficient evidence, still it would explain nothing as to the manner in which the mind perceives external objects. It relieves no difficulty. If the representative image be itself material, how can the mind take cognizance of it? If not material, how can it represent matter, and how can the mind know that it does represent correctly the external object?

State of the Matter since Reid.—Since the time of Dr. Reid, this theory of representative perception, at least in this non-egoistic form, has been for the most part abandoned, and philosophers have been content to take the ground indicated by consciousness, and the common sense of mankind, that in perception we take direct cognizance of the external object.

Position of Hamilton.—It remained for Sir W. Hamilton to complete the work which Dr. Reid began, by showing that the representative theory, in its finer or egoistic form, as held by Dr. Brown and others, is equally untenable or unsound; that it makes little difference whether we regard the image or idea, which we take to represent the external object, as something distinct from the mind itself, or whether we view it as a mere modification or state of the mind, so long as we make any thing of the sort the direct object of perception instead of the real external thing. Idealism is the result in either case, and philosophical skepticism the goal. In place of any and all such views, Hamilton maintains, with great power and earnestness, the doctrine of natural realism—that in perception we are cognizant immediately and directly of the external object.

As no other writer has so fully elaborated this department of science, it may be of service to present in this connection the chief points of his theory.

Chief Points of Hamilton's Theory of Perception.—All perception is immediate cognition; we perceive only what we apprehend as now and here existent; and hence what we perceive is either in our own organism, viewed as material, extended, etc., or else is in immediate correlation to it. The organism is, in perception, viewed as not-me; in sensation, as of the me.

What is given in Perception proper.—What we apprehend in perception proper is: 1. The primary qualities of body as pertaining to our own organism; 2. The secundo-primary qualities of bodies in correlation to it. (See Hamilton's division of qualities of bodies, as above.)

Primary Qualities of external Objects, how known.—The primary qualities of things external to our organism we do not perceive immediately, but only infer, from the effects produced on us by them. Neither in perception nor sensation do we apprehend immediately, or in itself, the external cause of our affection or sensation. That is always unknown to consciousness, known only by inference or conjecture.

External Existence, how learned.—The existence of the world without is apprehended not in a perception of the primary qualities of things external, but of the secundo-primary—i. e., in the consciousness that our movements are resisted by something external to our organism. This involves the consciousness of something external, resisting. The two things are conjunctly apprehended.

This presupposes what.—This experience presupposes the notion of space, and motion in space. These are inherent, instinctive native elements of thought, and it is idle to inquire how we come by them. Every perception of sensations out of, and distinct from, other sensations gives occasion for conceiving the idea of space. Outness involves it.

Points of Difference between this Theory and Reid's.—The system, as thus stated, differs in some respects materially from the doctrine of perception advanced by Dr. Reid, and generally adopted since his time by the English and Scotch philosophers. According to Hamilton, perception is not, as held by Reid and others, the conception of an object suggested by sensation, but the direct cognition of something. We do not merely conceive of the object as existing, and believe it to exist, we know it and perceive it to exist. Nor does sensation precede, and perception follow, as generally stated, but the two are, in time, conjunct, coëxistent. Nor do we perceive the secondary qualities of bodies, as such, but only infer them from our sensations. Neither do we perceive distant objects through a medium, as usually held, but what we perceive is either the organism itself, as affected thus and thus, or what is directly in contact with it, as affecting and resisting it. Extension and externality, again, are not first learned by touch, as Reid holds, and most subsequent writers, both English and American, but in other ways; the former, by the perception of the primary qualities of our own organism, as the seat of sensations distinct from other sensations elsewhere localized; the latter, by the resistance which we experience to our own locomotive force. Finally, sensation proper is not, as with Reid and others, an affection purely of the mind, but of mind and body as complex. Its subject is as much one as the other.