René Descartes Duperron, a few years later than Bacon (he was born in 1596, at La Haye, in Touraine, died 1650, at Stockholm) established the foundations of the deductive method of reasoning, and applied it in a manner which Bacon had apparently carefully avoided. Both Descartes and Bacon addressed themselves to the task of substituting for the old systems, a more comprehensive and useful spirit of philosophy; but while Bacon sought to accomplish this by persuading men to experiment and observation, Descartes commenced with the search for a first and self-evident ground of all knowledge. This, to him, is found in consciousness. The existence of Deity was a point which Bacon left untouched by reason, yet with Descartes it was the first proposition he sought to prove. He says: “I have always thought that the two questions of the existence of God and the nature of the soul, were the chief of those which ought to be demonstrated rather by philosophy than by theology, for although it is sufficient for us, the faithful, to believe in God, and that the soul does not perish with the body, it does not seem possible ever to persuade the infidels to any religion unless we first prove to them those two things by natural reason.” To prove this existence of God and the immortality of the soul, Descartes needed a firm starting point, one which no doubt could touch, one which no argument could shake. He found this point in the fact of his own existence. He could doubt everything else, but he could not doubt that he, the thinking doubter, existed. His own existence was the primal fact, the indubitable certainty, which served as the base for all other reasonings, hence his famous “Cogito ergo sum:”—I think, therefore I am. And although it has been fairly objected that Descartes did not exist because he thought, but existed and thought; it is nevertheless clear that it is only in the thinking that Descartes had the consciousness of his existence. The fact of Descartes’ existence was, to him, one above and beyond all logic. Evidence could not add to the certitude, no scepticism could impeach it. Whether or not we agree with the Cartesian philosophy, or the reasonings used to sustain it, we must admire the following four rules which he has given us, and which, with the view of consciousness in which we do not entirely concur, are the essential features of the basis of a considerable portion of Descartes’ system:— “1. Never to accept anything as true but what is evidently so; to admit nothing but what so clearly and distinctly presents itself as true, that there can be no reason to doubt it. “2. To divide every question into as many separate parts as possible, that each part being more easily conceived, the whole may be more intelligible. “3. To conduct the examination with order, beginning by that of objects the most simple, and therefore the easiest to be known, and ascending little by little up to knowledge of the most complex.