We say identified, because it really is so in Descartes' opinion; and this confirms what we have already advanced, that this philosopher did not offer an argument, but laid down a fact. According to him, the essence of the soul consists in thought; and as other schools of philosophy distinguish between substance and its acts, considering the mind in the first class, and thought in the second, so Descartes held that there was no distinction between mind and thought, that they were the same thing, that thought constituted the essence of the soul. "Although one attribute," he says, "suffices to make us know the substance, there is, nevertheless, in every substance one attribute, which constitutes its nature and its essence, and on which all the others depend. Extension in length, breadth, and depth, constitutes the essence of corporeal substance; and thought constitutes the nature of the substance which thinks."[9] From this it follows that Descartes, in laying down the principle, I think, therefore I exist, only declared a fact attested by consciousness; and so simple did he consider it, and so unique, that in evolving his system, he identified thought with the soul, and its essence with its existence. He was conscious of thought, and said: "this thought is my soul; I am." It is not now our purpose to weigh the value of this doctrine, but only to explain in what it consists.[(17)]
[CHAPTER XVIII.]
THE PRINCIPLE OF DESCARTES, CONTINUED.—HIS METHOD.
170. Descartes did not always express himself with, sufficient accuracy when announcing and explaining his principle; and hence his words have been misinterpreted. In the passage where he establishes consciousness of our own thought and existence as the foundation whereon all our cognitions must rest, he uses terms from which it can be inferred that he not only means to declare a fact, but that he also intends to afford a true argument. Nevertheless, if we read his words attentively, and compare them with one another, it will be evident that such was not his idea, although we should not sometimes be wrong in saying that he did not make sufficient account of the difference, which we have just pointed out, between an argument and the simple declaration of a fact; and that, when concentrating himself on himself, he did not have a sufficiently clear reflex knowledge of the manner in which he rested upon his fundamental principle. To convince ourselves of this, let us examine his own words: "While we thus reject every thing of which we can have the least doubt, and even feign that it is false, we easily suppose that there is no God, no heaven, no earth; that we have not a body: but we cannot in like manner suppose that we are not whilst we doubt the truth of all these things; for we experience so great repugnance to conceive that what thinks is not at the same time that it thinks, that notwithstanding all the most extravagant suppositions, we cannot help believing this conclusion, I think, therefore I am, to be true, and consequently the first and most certain to present itself to him who orders well his thoughts."[10]
In this passage we detect a true syllogism: whatever thinks, exists; but I think; therefore I exist. "We have," says Descartes, "so great repugnance to conceive that what thinks is not at the same time that it thinks;" which is the same as to say, whatever thinks, exists; and this, in scholastic terms, is to establish the major. He then says: "notwithstanding all the most extravagant suppositions, we cannot help believing this conclusion, I think, therefore I am, to be true;" which is equivalent to proving the minor, and the conclusion of the syllogism. We know that Descartes was somewhat taken up with the idea of proving at the same time that he was engaged in declaring. This was the general tendency of his age, and even the most ardent reformers with difficulty preserved themselves from the surrounding atmosphere. We encounter this same spirit throughout his meditations, admirably joined, however, with the spirit of observation.
But through these obscure or ambiguous explanations, what thought do we discover at the bottom of Descartes' system when we abstract his having, or not having, rendered himself an exact account of what he experienced? This thought: "By an effort of my mind I can doubt the truth of everything; but this effort has a limit in myself. When I turn my attention upon myself, upon the consciousness of my internal acts, upon my existence, doubt is at an end; it cannot extend so far: I find so great repugnance that the most extravagant suppositions cannot overcome it." This his very words show: besides declaring this fact, he rises to a general and undoubtedly true proposition; he draws a conclusion also very legitimate; but neither of these was at all necessary to the present case; neither seemed to explain well his opinion, but either served to confuse it.
171. Descartes did nothing more in this point than what all philosophers do; and strange as it may seem, he did not differ from the chiefs of the metaphysical school diametrically opposed to his own, that of Locke and Condillac. That man, in seeking to examine the origin of his cognitions, and the principles on which his certainty is based, encounters the fact of consciousness of his internal acts, that this consciousness produces a firm certainty, and that we can conceive nothing more certain, is a fact on which all ideologists agree, and which all establish, although not in the same words. The more we reflect on these matters, the more we discover in them the realization of a principle confirmed by reason and experience, that many truths are not new, but only presented under a new form, and that many systems are not new, but only expressed in new formulas.
172. Even the universal doubt of Descartes, rightly understood, is practised by every philosopher; whence we see that the basis of his system, opposed by many, is in fact adopted by all. In what does his method consist? It may all be reduced to these two points: I. I wish to doubt of everything: II. When I wish to doubt of myself, I cannot.