[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.|