(1596-1650)
RENÉ DESCARTES.
he broad scope of literature is illustrated by its inclusion of the writings of René Descartes (Latinized, Renatus Cartesius). Deliberately turning away from books, and making naught alike of learned precedent and literary form, he yet could not but avail himself unconsciously of the heritage which he had discarded.
This notable figure in seventeenth-century philosophy was born of ancient family at La Haye, in Touraine, France, March 31st, 1596; and died at Stockholm, Sweden, February 11th, 1650. From a pleasant student life of eight years in the Jesuit college at La Flèche, he went forth in his seventeenth year with unusual acquirements in mathematics and languages, but in deep dissatisfaction with the long dominant scholastic philosophy and the whole method prescribed for arriving at truth. In a strong youthful revolt, his first step was a decision to discharge his mind of all the prejudices into which his education had trained his thinking. As a beginning in this work he went to Paris, for observation of facts and of men. There, having drifted through a twelvemonth of moderate dissipation, he secluded himself for nearly two years of mathematical study, as though purposing to reduce his universe to an equation in order to solve it. The laws of number he could trust, since their lines configured the eternal harmony.
At the age of twenty-one he entered on a military service of two years in the army of the Netherlands, and then of about two years in the Bavarian army. From 1621, for about four years, he was roaming as an observer of men and nature in Germany, Belgium, and Italy, afterward sojourning in Paris about three and a half years. In 1629 he began twenty years of study and authorship in practical seclusion in Holland. His little work, 'Discours de la Méthode' (Leyden, 1637), is often declared to have been the basis for a reconstitution of the science of thought. It would now perhaps be viewed by the majority of critics rather as a necessary clearing of antiquated rubbish from the ground on which the new construction was to rise. Next to it among his works are usually ranked 'Meditationes de Prima Philosophia,' and 'Principia Philosophiæ.'
The long sojourn in Holland was ended in September 1649, in response to an urgent invitation from the studious young Queen Christina of Sweden, who wanted the now famous philosopher as an ornament to her court. After some hesitancy he sailed for Stockholm, where only five months afterward he died.
It has been said of Descartes that he was a spectator rather than an active worker in affairs. He was no hero, no patriot, no adherent of any party. He entered armies, but not from love of a cause; the army was a sphere in which he could closely observe the aspects of human life. He was never married, and probably had little concern with love. His attachment to a few friends seems to have been sincere. For literature as such he cared little. Erudition, scholarship, historic love, literary elegance, were nothing to him. Art and æsthetics did not appeal to him. Probably he was not a great reader, even of philosophic writers. He delighted in observing facts with a view to finding, stating, and systematizing their relations in one all-comprehending scheme. He never allowed himself to attack the Church in either its doctrine or its discipline. As a writer, though making no attempt at elegance in style, he is deemed remarkably clear and direct when the abstruseness of his usual themes is considered.
Descartes's method in philosophy gives signs of formation on the model of a process in mathematics. In all investigations he would ascertain first what must exist by necessity; thus establishing axioms evidenced in all experience, because independent of all experience. The study of mathematics for use in other departments drew him into investigations whose results made it a new science. He reformed its clumsy nomenclature, also the algebraic use of letters for quantities; he introduced system into the use of exponents to denote the powers of a quantity, thus opening the way for the binomial theorem; he was the first to throw clear light on the negative roots of equations; his is the theorem by use of which the maximum number of positive or negative roots of an equation can be ascertained. Analytical geometry originated with his investigation of the nature and origin of curves.
His mathematical improvements opened the way for the reform of physical science and for its immense modern advance. In his optical investigations he established the law of refraction of light. His ingenious theory of the vortices—tracing gravity, magnetism, light, and heat, to the whirling or revolving movements of the molecules of matter with which the universe is filled—was accepted as science for about a quarter of a century.
In mental science Descartes's primary instrument for search of truth was Doubt: everything was to be doubted until it had been proved. This was provisional skepticism, merely to provide against foregone conclusions. It was not to preclude belief, but to summon and assure belief as distinct from the inane submission to authority, to prejudice, or to impulse. In this process of doubting everything, the philosopher comes at last to one fact which he cannot doubt—the fact that he exists; for if he did not exist he could not be thinking his doubt. Cogito, ergo sum is one point of absolute knowledge; it is a clear and ultimate perception.
The first principle of his philosophy is, that our consciousness is truthful in its proper sphere, also that our thought is truthful and trustworthy under these two conditions—when the thought is clear and vivid, and when it is held to a theme utterly distinct from every other theme; since it is impossible for us to believe that either man who thinks, or the universe concerning which he thinks, is organized on the basis of a lie. There are "necessary truths," and they are discoverable.
A second principle is, the inevitable ascent of our thought from the fragmentary to the perfect, from the finite to the infinite. Thus the thought of the infinite is an "innate idea," a part of man's potential consciousness. This principle (set forth in one of the selections given herewith) is the Cartesian form of the a priori argument for the Divine existence, which like other a priori forms is viewed by critics not as a proof in pure logic, but as a commanding and luminous appeal to man's entire moral and intellectual nature.
A third principle is, that the material universe is necessarily reduced in our thought ultimately to two forms, extension and local movement—extension signifying matter, local movement signifying force. There is no such thing as empty space; there are no ultimate indivisible atoms; the universe is infinitely full of matter.
A fourth principle is, that the soul and matter are subsistences so fundamentally and absolutely distinct that they cannot act in reciprocal relations. This compelled Descartes to resort to his strained supposition that all correspondence or synchronism between bodily movements and mental or spiritual activities is merely reflex or automatic, or else is produced directly by act of Deity. For relief from this violent hypothesis, Leibnitz modified the Cartesian philosophy by his famous theory of a pre-established harmony.
Descartes did a great work, but it was not an abiding reconstruction: indeed, it was not construction so much as it was a dream—one of the grandest and most suggestive in the history of thought. Its audacious disparagement of the whole scholastic method startled Europe, upon the dead air of whose philosophy it came as a refreshing breath of transcendental thought. Its suggestions and inspirations are traceable as a permanent enrichment, though its vast fabric swiftly dissolved. The early enthusiasm for it in French literary circles and among professors in the universities of Holland scarcely outlasted a generation. Within a dozen years after the philosopher's death, the Cartesian philosophy was prohibited by ecclesiastical authorities and excluded from the schools. In the British Isles and in Germany the system has been usually considered as an interesting curiosity in the cabinet of philosophies. Yet the unity of all truth through relations vital, subtle, firm, and universal, though seen only in a vision of the night, abides when the night is gone.
With the impressive and noteworthy 'Discours de la Méthode' (Leyden, 1637), were published three essays supporting it: 'La Dioptrïque,' 'Les Météores,' 'La Géométrie.' Of his other works, the most important are 'Meditationes de Prima Philosophia' (Paris, 1641; Amsterdam, 1642), and 'Principia Philosophiæ' (Amsterdam, 1644). A useful English translation of his most important writings, with an introduction, is by John Veitch, LL.D.,—'The Method, Meditations, and Selections from the Principles' (Edinburgh, 1853; 6th ed., Blackwoods, Edinburgh and London, 1879). See also, English translations of portions of his philosophical works, by W. Cunningham (1877), Lowndes (1878), Mahaffy (1880), Martineau (1885), Henry Rogers, Huxley, and L. Stephen.
For his Life, see 'Vie de Descartes,' by Baillet (2 vols. 1691); 'Descartes sa Vie,' etc., by Millet (2 vols. 1867-71); 'Descartes and his School,' by Kuno Fischer (English translation, 1887).
OF CERTAIN PRINCIPLES OF ELEMENTARY LOGICAL THOUGHT
From the 'Discourse on Method'
As a multitude of laws often only hampers justice, so that a State is best governed when, with few laws, these are rigidly administered; in like manner, instead of the great number of precepts of which Logic is composed, I believed that the four following would prove perfectly sufficient for me, provided I took the firm and unwavering resolution never in a single instance to fail in observing them.
The first was never to accept anything for true which I did not clearly know to be such; that is to say, carefully to avoid precipitancy and prejudice, and to comprise nothing more in my judgment than what was presented to my mind so clearly and distinctly as to exclude all ground of doubt.
The second, to divide each of the difficulties under examination into as many parts as possible, and as might be necessary for its adequate solution.
The third, to conduct my thoughts in such order that, by commencing with objects the simplest and easiest to know, I might ascend by little and little, and as it were step by step, to the knowledge of the more complex; assigning in thought a certain order even to those objects which in their own nature do not stand in a relation of antecedence and sequence.
And the last, in every case to make enumerations so complete, and reviews so general, that it might be assured that nothing was omitted.
The long chains of simple and easy reasonings by means of which geometers are accustomed to reach the conclusions of their most difficult demonstrations, had led me to imagine that all things to the knowledge of which man is competent are mutually connected in the same way, and that there is nothing so far removed from us as to be beyond our reach, or so hidden that we cannot discover it, provided only we abstain from accepting the false for the true, and always preserve in our thoughts the order necessary for the deduction of one truth from another. And I had little difficulty in determining the objects with which it was necessary to commence, for I was already persuaded that it must be with the simplest and easiest to know, and, considering that of all those who have hitherto sought truth in the Sciences, the mathematicians alone have been able to find any demonstrations,—that is, any certain and evident reasons,—I did not doubt but that such must have been the rule of their investigations. I resolved to commence, therefore, with the examination of the simplest objects, not anticipating, however, from this any other advantage than that to be found in accustoming my mind to the love and nourishment of truth, and to a distaste for all such reasonings as were unsound. But I had no intention on that account of attempting to master all the particular sciences commonly denominated Mathematics: but observing that however different their objects, they all agree in considering only the various relations or proportions subsisting among those objects, I thought it best for my purpose to consider these proportions in the most general form possible; without referring them to any objects in particular, except such as would most facilitate the knowledge of them, and without by any means restricting them to these, that afterwards I might thus be the better able to apply them to every other class of objects to which they are legitimately applicable. Perceiving, further, that in order to understand these relations I should sometimes have to consider them one by one, and sometimes only to bear them in mind, or embrace them in the aggregate, I thought that in order the better to consider them individually, I should view them as subsisting between straight lines, than which I could find no objects more simple, or capable of being more distinctly represented to my imagination and senses; and on the other hand, that in order to retain them in the memory, or embrace an aggregate of many, I should express them by certain characters the briefest possible. In this way I believed that I could borrow all that was best both in geometrical analysis and in algebra, and correct all the defects of the one by help of the other.
AN ELEMENTARY METHOD OF INQUIRY
From the 'Discourse on Method'
Seeing that our senses sometimes deceive us, I was willing to suppose that there existed nothing really such as they presented to us; and because some men err in reasoning and fall into paralogisms, even on the simplest matters of geometry, I, convinced that I was as open to error as any other, rejected as false all the reasonings I had hitherto taken for demonstrations; and finally, when I considered that the very same thoughts (presentations) which we experience when awake may also be experienced when we are asleep, while there is at that time not one of them true, I supposed that all the objects (presentations) that had ever entered into my mind when awake had in them no more truth than the illusions of my dreams. But immediately upon this I observed that whilst I thus wished to think that all was false, it was absolutely necessary that I, who thus thought, should be somewhat; and as I observed that this truth,—"I think, hence I am,"—was so certain and of such evidence that no ground of doubt, however extravagant, could be alleged by the skeptics capable of shaking it, I concluded that I might without scruple accept it as the first principle of the philosophy of which I was in search.
In the next place, I attentively examined what I was, and as I observed that I could suppose that I had no body, and that there was no world nor any place in which I might be; but that I could not therefore suppose that I was not; and that on the contrary, from the very circumstance that I thought to doubt of the truth of other things, it most clearly and certainly followed that I was; while on the other hand, if I had only ceased to think, although all the other objects which I had ever imagined had been in reality existent, I would have had no reason to believe that I existed; I thence concluded that I was a substance whose whole essence or nature consists only in thinking, and which, that it may exist, has need of no place, nor is dependent on any material thing; so that "I"—that is to say, the mind by which I am what I am—is wholly distinct from the body, and is even more easily known than the latter, and is such that although the latter were not, it would still continue to be all that it is.
After this I inquired in general into what is essential to the truth and certainty of a proposition; for since I had discovered one which I knew to be true, I thought that I must likewise be able to discover the ground of this certitude. And as I observed that in the words "I think, hence I am," there is nothing at all which gives me assurance of their truth beyond this, that I see very clearly that in order to think it is necessary to exist,—I concluded that I might take, as a general rule, the principle that all the things which we very clearly and distinctly conceive are true; only observing however that there is some difficulty in rightly determining the objects which we distinctly conceive.
In the next place, from reflecting on the circumstance that I doubted, and that consequently my being was not wholly perfect (for I clearly saw that it was a greater perfection to know than to doubt), I was led to inquire whence I had learned to think of something more perfect than myself; and I clearly recognized that I must hold this notion from some Nature which in reality was more perfect. As for the thoughts of many other objects external to me, as of the sky, the earth, light, heat, and a thousand more, I was less at a loss to know whence these came; for since I remarked in them nothing which seemed to render them superior to myself, I could believe that if these were true, they were dependences on my own nature in so far as it possessed a certain perfection; and if they were false, that I held them from nothing,—that is to say, that they were in me because of a certain imperfection of my nature. But this could not be the case with the idea of a Nature more perfect than myself: for to receive it from nothing was a thing manifestly impossible; and because it is not less repugnant that the more perfect should be an effect of and dependence on the less perfect, than that something should proceed from nothing, it was equally impossible that I could hold it from myself: accordingly it but remained that it had been placed in me by a Nature which was in reality more perfect than mine, and which even possessed within itself all the perfections of which I could form any idea,—that is to say, in a single word, which was God....
I was disposed straightway to search for other truths; and when I had represented to myself the object of the geometers, which I conceived to be a continuous body, or a space indefinitely extended in length, breadth, and height or depth, divisible into divers parts which admit of different figures and sizes, and of being moved or transposed in all manner of ways (for all this the geometers suppose to be in the object they contemplate), I went over some of their simplest demonstrations. And in the first place, I observed that the great certitude which by common consent is accorded to these demonstrations is founded solely upon this, that they are clearly conceived in accordance with the rules I have already laid down. In the next place, I perceived that there was nothing at all in these demonstrations which could assure me of the existence of their object: thus, for example, supposing a triangle to be given, I distinctly perceived that its three angles were necessarily equal to two right angles, but I did not on that account perceive anything which could assure me that any triangle existed; while on the contrary, recurring to the examination of the idea of a Perfect Being, I found that the existence of the Being was comprised in the idea in the same way that the equality of its three angles to two right angles is comprised in the idea of a triangle, or as in the idea of a sphere, the equidistance of all points on its surface from the centre, or even still more clearly; and that consequently it is at least as certain that God, who is this Perfect Being, is, or exists, as any demonstration of geometry can be.
THE IDEA OF GOD
From the 'Meditations'
There only remains, therefore, the idea of God, in which I must consider whether there is anything that cannot be supposed to originate with myself. By the name God I understand a substance infinite, eternal, immutable, independent, all-knowing, all-powerful, and by which I myself, and every other thing that exists,—if any such there be,—were created. But these properties are so great and excellent, that the more attentively I consider them, the less I feel persuaded that the idea I have of them owes its origin to myself alone. And thus it is absolutely necessary to conclude, from all that I have before said, that God exists; for though the idea of substance be in my mind owing to this,—that I myself am a substance,—I should not however have the idea of an infinite substance, seeing I am a finite being, unless it were given me by some substance in reality infinite.
And I must not imagine that I do not apprehend the infinite by a true idea, but only by the negation of the finite, in the same way that I comprehend repose and darkness by the negation of motion and light: since, on the contrary, I clearly perceive that there is more reality in the infinite substance than in the finite, and therefore that in some way I possess the perception (notion) of the infinite before that of the finite, that is, the perception of God before that of myself; for how could I know that I doubt, desire, or that something is wanting to me, and that I am not wholly perfect, if I possessed no idea of a being more perfect than myself, by comparison with which I knew the deficiencies of my nature?
And it cannot be said that this idea of God is perhaps materially false, and consequently that it may have arisen from nothing (in other words, that it may exist in me from my imperfection), as I before said of the ideas of heat and cold, and the like; for on the contrary, as this idea is very clear and distinct, and contains in itself more objective reality than any other, there can be no one of itself more true, or less open to the suspicion of falsity.
The idea, I say, of a being supremely perfect and infinite, is in the highest degree true; for although perhaps we may imagine that such a being does not exist, we nevertheless cannot suppose that this idea represents nothing real, as I have already said of the idea of cold. It is likewise clear and distinct in the highest degree, since whatever the mind clearly and distinctly conceives as real or true, and as implying any perfection, is contained entire in this idea. And this is true, nevertheless, although I do not comprehend the infinite, and although there may be in God an infinity of things that I cannot comprehend, nor perhaps even compass by thought in any way; for it is of the nature of the infinite that it should not be comprehended by the finite: and it is enough that I rightly understand this, and judge that all which I clearly perceive, and in which I know there is some perfection, and perhaps also an infinity of properties of which I am ignorant, are formally or eminently in God, in order that the idea I have of him may become the most true, clear, and distinct of all the ideas in my mind.
But perhaps I am something more than I suppose myself to be; and it may be that all those perfections which I attribute to God in some way exist potentially in me, although they do not yet show themselves and are not reduced to act. Indeed, I am already conscious that my knowledge is being increased and perfected by degrees; and I see nothing to prevent it from thus gradually increasing to infinity, nor any reason why, after such increase and perfection, I should not be able thereby to acquire all the other perfections of the Divine nature; nor in fine, why the power I possess of acquiring those perfections, if it really now exist in me, should not be sufficient to produce the ideas of them. Yet on looking more closely into the matter I discover that this cannot be; for in the first place, although it were true that my knowledge daily acquired new degrees of perfection, and although there were potentially in my nature much that was not as yet actually in it, still all these excellences make not the slightest approach to the idea I have of the Deity, in whom there is no perfection merely potentially, but all actually existent; for it is even an unmistakable token of imperfection in my knowledge, that it is augmented by degrees. Further, although my knowledge increase more and more, nevertheless I am not therefore induced to think that it will ever be actually infinite, since it can never reach that point beyond which it shall be incapable of further increase. But I conceive God as actually infinite, so that nothing can be added to his perfection. And in fine, I readily perceive that the objective being of an idea cannot be produced by a being that is merely potentially existent,—which properly speaking is nothing, but only a being existing formally or actually.
And truly, I see nothing in all that I have now said which it is not easy for any one who shall carefully consider it, to discern by the natural light; but when I allow my attention in some degree to relax, the vision of my mind being obscured and as it were blinded by the images of sensible objects, I do not readily remember the reason why the idea of a being more perfect than myself must of necessity have proceeded from a being in reality more perfect. On this account I am here desirous to inquire further whether I, who possess this idea of God, could exist supposing there were no God. And I ask, from whom could I in that case derive my existence? Perhaps from myself, or from my parents, or from some other causes less perfect than God; for anything more perfect, or even equal to God, cannot be thought or imagined. But if I were independent of every other existence, and were myself the author of my being, I should doubt of nothing, I should desire nothing, and in fine, no perfection would be wanting to me; for I should have bestowed upon myself every perfection of which I possess the idea, and I should thus be God. And it must not be imagined that what is now wanting to me is perhaps of more difficult acquisition than that of which I am already possessed; for on the contrary, it is quite manifest that it was a matter of much higher difficulty that I, a thinking being, should arise from nothing, than it would be for me to acquire the knowledge of many things of which I am ignorant, and which are merely the accidents of a thinking substance; and certainly, if I possessed of myself the greater perfection of which I have now spoken,—in other words, if I were the author of my own existence,—I would not at least have denied to myself things that may be more easily obtained, as that infinite variety of knowledge of which I am at present destitute. I could not indeed have denied to myself any property which I perceive is contained in the idea of God, because there is none of these that seems to be more difficult to make or acquire; and if there were any that should happen to be more difficult to acquire, they would certainly appear so to me (supposing that I myself were the source of the other things I possess), because I should discover in them a limit to my power.