History of the Intellectual Development of Europe, Volume I (of 2) / Revised Edition

by John William Draper

(4.) Of the possibility of a criterion of truth. An absolute criterion of truth must at once accredit itself, as well as other things. At a very early period in philosophy the senses were detected as being altogether untrustworthy. On numberless occasions, instead of accrediting, they discredit themselves. A stick, having a spark of fire at one end, gives rise to the appearance of a circle of light when it is turned round quickly. The rainbow seems to be an actually existing arch until the delusion is detected by our going to the place over which it seems to rest. Nor is it alone as respects things for which there is an exterior basis or foundation, such as the spark of fire in one of these cases, and the drops of water in the other. Each of our organs of sense can palm off delusions of the most purely fictitious kind. The eye may present apparitions as distinct as the realities among which they place themselves; the ear may annoy us with the continual repetition of a murmuring sound, or parts of a musical strain, or articulate voices, though we well know that it is all a delusion; and in like manner, in their proper way, in times of health, and especially in those of sickness, will the other senses of taste, and touch, and smell practise upon us their deceptions.

This being the case, how shall we know that any information derived from such unfaithful sources is true? Pythagoras rendered a great service in telling us to remember that we have within ourselves a means of detecting fallacy and demonstrating truth. What is it that assures us of the unreality of the fiery circle, the rainbow, the spectre, the voices, the crawling of insects upon the skin? Is it not reason? To reason may we not then trust?

With such facts before us, what a crowd of inquiries at once presses upon our attention—inquiries which even in modern times have occupied the thoughts of the greatest metaphysicians. Shall we begin our studies by Uncertainties in philosophizing. examining sensations or by examining ideas? Shall we say with Descartes that all clear ideas are true? Shall we inquire with Spinoza whether we have any ideas independent of experience? With Hobbes, shall we say that all our thoughts are begotten by and are the representatives of objects exterior to us; that our conceptions arise in material motions pressing on our organs, producing motion in them, and so affecting the mind; that our sensations do not correspond with outward qualities; that sound and noise belong to the bell and the air, and not to the mind, and, like colour, are only agitations occasioned by the object in the brain; that imagination is a conception gradually dying away after the act of sense, and is nothing more than a decaying sensation; that memory is the vestige of former impressions, enduring for a time; that forgetfulness is the obliteration of such vestiges; that the succession of thought is not indifferent, at random, or voluntary, but that thought follows thought in a determinate and predestined sequence; that whatever we imagine is finite, and hence we cannot conceive of the infinite, nor think of anything not subject to sense? Shall we say with Locke that there are two sources of our ideas, sensation and reflection; that the mind cannot know things directly, but only through ideas? Shall we suggest with Leibnitz that reflection is nothing more than attention to what is passing in the mind, and that between the mind and the body there is a sympathetic synchronism? With Berkeley shall we assert that there is no other reason for inferring the existence of matter itself than the necessity of having some synthesis for its attributes; that the objects of knowledge are ideas and nothing else; and that the mind is active in sensation? Shall we listen to the demonstration of Hume, that, if matter be an unreal fiction, the mind is not less so, since it is no more than a succession of impressions and ideas; that our belief in causation is only the consequence of habit; and that we have better proof that night is the cause of day, than of thousands of other cases in which we persuade ourselves that we know the right relation of cause and effect; that from habit alone we believe the future will resemble the past? Shall we infer with Condillac that memory is only transformed sensation, and comparison double attention; that every idea for which we cannot find an exterior object is destitute of significance; that our innate ideas come by development, and that reasoning and running are learned together. With Kant shall we conclude that there is but one source of knowledge, the union of the object and the subject—but two elements thereof, space and time; and that they are forms of sensibility, space being a form of internal sensibility, and time both of internal and external, but neither of them having any objective reality; and that the world is not known to us as it is, but only as it appears?

Remarks on the criterion.

I admit the truth of the remark of Posidonius that a man might as well be content to die as to cease philosophizing; for, if there are contradictions in philosophy, there are quite as many in life. In the light of this remark, I shall therefore not hesitate to offer a few suggestions respecting the criterion of human knowledge, undiscouraged by the fact that so many of the ablest men have turned their attention to it. In this there might seem to be presumption, were it not that the advance of the sciences, and especially of human physiology has brought us to a more elevated point of view, and enabled us to see the state of things much more distinctly than was possible for our predecessors.

Defective information of the old philosophy.

I think that the inability of ancient philosophers to furnish a true solution of this problem was altogether owing to the imperfect, and, indeed, erroneous idea they had of the position of man. They gave too much weight to his personal individuality. In the mature period of his life they regarded him as isolated, independent, and complete in himself. They forgot that this is only a momentary phase in his existence, which, commencing from small beginnings, exhibits a continuous expansion or progress. From a single cell, scarcely more than a step above the inorganic state, not differing, as we may infer both from the appearance it offers and the forms through which it runs in the earlier stages of life, from the cell out of which any other animal or plant, even the humblest, is derived, a passage is made Necessity of a more general conception as to man. through form after form in a manner absolutely depending upon surrounding physical conditions. The history is very long, and the forms are very numerous, between the first appearance of the primitive trace and the hoary aspect of seventy years. It is not correct to take one moment in this long procession and make it a representative of the whole. It is not correct to say, even if the body of the mature man undergoes unceasing changes to an extent implying the reception, incorporation, and dismissal of nearly a ton and a half of material in the course of a year, that in this flux of matter there is not only a permanence of form, but, what is of infinitely more importance, an unchangeableness in his intellectual powers. It is not correct to say this; indeed, it is wholly untrue. The intellectual principle passes forward in a career as clearly marked as that in which the body runs. Even if we overlook the time antecedent to birth, how complete is the imbecility of his The whole cycle must be included, early days! The light shines upon his eyes, he sees not; sounds fall upon his ear, he hears not. From these low beginnings we might describe the successive re-enforcements through infancy, childhood, and youth to maturity. And what is the result to which all this carries us? Is it not that, in the philosophical contemplation of man, we are constrained to reject the idea of personality, of individuality, and to adopt that of a cycle of progress; to abandon all contemplation of his mere substantial form, and consider his abstract relation? All organic forms, if compared together and examined from one common point of view, are found to be constructed upon an identical scheme. It is as in some mathematical expression containing constants and variables; the actual result changes accordingly as we assign successively different values to the variables, yet in those different results, no matter how numerous they may be, the original formula always exists. From such a universal conception of the condition and career of man, we rise at once to the apprehension of his relations to others like himself—that is to say, his relations as a member of society. We perceive, in this light, that society must run a course the counterpart of that we have traced for the and also his race connexions. individual, and that the appearance of isolation presented by the individual is altogether illusory. Each individual man drew his life from another, and to another man he gives rise, losing, in point of fact, his aspect of individuality when these his race connexions are considered. One epoch in life is not all life. The mature individual cannot be disentangled from the multitudinous forms through which he has passed; and, considering the nature of his primitive conception and the issue of his reproduction, man cannot be separated from his race.

By the aid of these views of the nature and relationship of man, we can come to a decision respecting his possession of a criterion of truth. In the earliest moments of his existence he can neither feel nor think, and the universe is to him as though it did not exist. Considering the progress of his sensational powers—his sight, hearing, touch, etc.—these, as his cycle advances to its maximum, become, by nature or by education, more and more perfect; but never, at the best, as the ancient philosophers well knew, are they trustworthy. And so of his intellectual powers. They, too, begin in feebleness and gradually expand. The mind alone is no more to be relied on than the organs of sense alone. If any doubt existed on this point, the study of the phenomena of dreaming is sufficient to remove it, for dreaming manifests to us how wavering and unsteady is the mind in its operations when it is detached from the solid support of the organs of sense. How true is the remark of Philo the Jew, that the mind is like the eye; for, though it may see all other objects, it cannot see itself, and therefore cannot judge of itself. And thus we may conclude that neither are the senses to be trusted alone, nor is the mind to be trusted alone. In the conjoint action of the two, by reason of the mutual checks established, a far higher degree of certainty is attained to, yet even in this, the utmost vouchsafed to the individual, there is not, as both Greeks and Indians ascertained, an absolute sureness. It was the knowledge of this which extorted from them so many melancholy complaints, which threw them into an intellectual despair, and made them, by applying the sad determination to which they had come to the course of their daily life, sink down into indifference and infidelity.

But yet there is something more in reserve for man. Let him cast off the clog of individuality, and remember that he has race connexions—connexions which, in this matter of a criterion of truth, indefinitely increase his chances of certainty. If he looks with contempt on the opinions of his childhood, with little consideration on those of his youth, with distrust on those of his manhood, what will he say about the opinions of his race? Do not such considerations teach us that, through all these successive conditions, the criterion of truth is ever advancing in precision and power, and that its maximum is found in the unanimous opinion of the whole human race?

Though no absolute criterion exists, a practical one does.