His publications. 84. In 1637 he broke upon the world with a volume containing the Discourse upon Method, the Dioptrics, the Meteors, and the Geometry. It is only with the first that we are for the present concerned.[227] In this discourse, the most interesting perhaps of Descartes’ writings, on account of the picture of his life, and of the progress of his studies that it furnishes, we find the Cartesian metaphysics, which do not consist of many articles, almost as fully detailed as in any of his later works. In the Meditationes de Prima Philosophia, published in Latin, 1641, these fundamental principles are laid down again more at length. He invited the criticism of philosophers on these famous Meditations. They did not refuse the challenge; and seven sets of objections, from as many different quarters, with seven replies from Descartes himself, are subjoined to the later editions of the Meditations. The Principles of Philosophy, published in Latin in 1644, contains what may be reckoned the final statement, which occupies most of the first book, written with uncommon conciseness and precision. The beauty of philosophical style which distinguished Descartes is never more seen than in this first book of the Principia, the translation of which was revised by Clerselier, an eminent friend of the author. It is a contrast at once to the elliptical brevity of Aristotle, who hints, or has been supposed to hint, the most important positions in a short clause, and to the verbose, figurative declamation of many modern metaphysicians. In this admirable perspicuity Descartes was imitated by his disciples Arnaud and Malebranche, especially the former. His unfinished posthumous treatise, the “Inquiry after Truth by Natural Reason,” is not carried farther than a partial development of the same leading principles of Cartesianism. There is consequently a great deal of apparent repetition in the works of Descartes, but such as on attentive consideration will show, not perhaps much real variance, but some new lights that had occurred to the author in the course of his reflections.[228]
[227] Id. p. 121-212.
[228] A work has lately been published, Essais Philosophiques, suivis de la Métaphysique de Descartes resembleé et mise en ordre, par L. A. Gruyer, 4 vols. Bruxelles, 1832. In the fourth volume we find the metaphysical passages in the writings of Descartes, including his correspondence, arranged methodically in his own words, but with the omission of a large part of the objections to the Meditations and of his replies. I did not, however, see this work in time to make use of it.
He begins by doubting all. 85. In pursuing the examination of the first principles of knowledge, Descartes perceived not only that he had cause to doubt of the various opinions he had found current among men, from that very circumstance of their variety, but that the sources of all that he had received for truth themselves, namely, the senses, had afforded him no indisputable certainty. He began to recollect how often he had been misled by appearances, which had at first sight given no intimation of their fallacy, and asked himself in vain, by what infallible test he could discern the reality of external objects, or at least their conformity to his idea of them. The strong impressions made in sleep led him to inquire whether all he saw and felt might not be in a dream. It was true that there seemed to be some notions more elementary than the rest, such as extension, figure, duration, which could not be reckoned fallacious; nor could he avoid owning that, if there were not an existing triangle in the world, the angles of one conceived by the mind, though it were in sleep, must appear equal to two right angles. But even in this certitude of demonstration he soon found something deficient; to err in geometrical reasoning is not impossible: why might he not err in this; especially in a train of consequences, the particular terms of which are not at the same instant present to the mind. But above all, there might be a superior being, powerful enough and willing to deceive him. It was no kind of answer to treat this as improbable, or as an arbitrary hypothesis. He had laid down as a maxim that nothing could be received as truth which was not demonstrable, and in one place, rather hyperbolically, and indeed extravagantly in appearance, says that he made little difference between merely probable and false suppositions; meaning this, however, as we may presume, in the sense of geometers, who would say the same thing.
His first step in knowledge. 86. But, divesting himself thus of all belief in what the world deemed most unquestionable, plunged in an abyss, as it seemed for a time, he soon found his feet on a rock, from which he sprang upwards to an unclouded sun. Doubting all things, abandoning all things, he came to the question, what is it that doubts and denies? Something it must be; he might be deceived by a superior power, but it was he that was deceived. He felt his own existence; the proof of it was that he did feel it; that he had affirmed, that he now doubted, in a word, that he was a thinking substance. Cogito: Ergo sum—this famous enthymem of the Cartesian philosophy veiled in rather formal language, that which was to him, and must be to us all, the eternal basis of conviction, which no argument can strengthen, which no sophistry can impair, the consciousness of a self within, a percipient indivisible Ego.[229] The only proof of this is that it admits of no proof, that no man can pretend to doubt of his own existence with sincerity, or to express a doubt without absurd and inconsistent language.
[229] This word, introduced by the Germans, or originally perhaps by the old Cartesians, is rather awkward, but far less so than the English pronoun I, which is also equivocal in sound. Stewart has adopted it as the lesser evil, and it seems reasonable not to scruple a word so convenient, if not necessary, to express the unity of the conscious principle. If it had been employed earlier, I am apt to think that some great metaphysical extravagances would have been avoided, and some fundamental truths more clearly apprehended. Fichte is well known to have made the grand division of Ich and Nicht Ich, Ego and Non Ego, the basis of his philosophy; in other words, the difference of subjective and objective reality.
His mind. 87. The scepticism of Descartes, it appears, which is merely provisional, is not at all similar to that of the Pyrrhonists, though some of his arguments may have been shafts from their quiver. |Not sceptical.| Nor did he make use, which is somewhat remarkable, of the reasonings afterwards employed by Berkley against the material world, though no one more frequently distinguished than Descartes between the objective reality, as it was then supposed to be, of ideas in the mind, and the external or sensible reality of things. Scepticism, in fact, was so far from being characteristic of his disposition, that his errors sprang chiefly from the opposite source, little as he was aware of it, from an undue positiveness in theories which he could not demonstrate, or even render highly probable.[230]
[230] One of the rules Descartes lays down in his posthumous art of logic, is that we ought never to busy ourselves except about objects concerning which our understanding appears capable of acquiring an unquestionable and certain knowledge, vol. xi., p. 204. This is at least too unlimited a proposition, and would exclude, not indeed all probability, but all inquiries which must by necessity end in nothing more than probability. Accordingly, we find in the next pages, that he made little account of any sciences but arithmetic and geometry, or such others as equal them in certainty. “From all this,” he concludes, “we may infer, not that arithmetic and geometry are the only sciences which we must learn, but that he who seeks the road to truth should not trouble himself with any object of which he cannot have as certain a knowledge, as of arithmetical and geometrical demonstrations.” It is unnecessary to observe what havoc this would make with investigations, even in physics, of the highest importance to mankind.
Beattie, in the essay on Truth, part ii. chap. 2, has made some unfounded criticisms on the scepticism of Descartes, and endeavours to turn into ridicule his, Cogito; ergo sum. Yet if any one should deny his own, or our existence, I do not see how we could refute him, were he worthy of refutation, but by some such language; and, in fact, it is what Beattie himself says, more paraphrastically, in answering Hume.
He arrives at more certainty. 88. The certainty of an existing Ego easily led him to that of the operations of the mind, called afterwards by Locke ideas of reflection, the believing, doubting, willing, loving, fearing, which he knew by consciousness, and indeed by means of which alone he knew that the Ego existed. He now proceeded a step farther; and reflecting on the simplest truths of arithmetic and geometry, saw that it was as impossible to doubt of them as of the acts of his mind. But as he had before tried to doubt even of these, on the hypothesis that he might be deceived by a superior intelligent power, he resolved to inquire whether such a power existed, and if it did, whether it could be a deceiver. The affirmative of the former, and the negative of the latter question Descartes established by that extremely subtle reasoning so much celebrated in the seventeenth century, but which has less frequently been deemed conclusive in later times. It is at least that which no man, not fitted by long practise for metaphysical researches, will pretend to embrace.