Doubt, Knowledge and the Cogito in Descartes’ Meditations

Descartes published his Meditations in First Philosophy in 1641. A French translation from the original Latin, which he saw and approved followed six years later. The words ‘in First Philosophy’ indicate that the Meditations attack fundamental questions, the chief of them being the nature of knowledge and the nature of man. I shall deal almost entirely with his treatment of the first, the nature of knowledge; even when the two questions become mixed up, as they notoriously do, I shall not encroach on to the second, the nature of man. The Meditations were intended to confirm Descartes’ reputation as a philosopher (he was already pre-eminent as a mathematician and a scientist) and, to increase their impact, they were accompanied in their first publication by a series of comments solicited from notable theologians and philosophers together with Descartes’ replies. These comments are called the Objections and numbered from one to six, but it is only an accident that there are six Meditations and six Objections. There are six Objections because there are six objectors (that is not quite true, the sixth Objection being a collection of comments from several people) and each Objection ranges over the whole work, although, of course, the different commentators focused upon the parts they found important or questionable. Many of the Objections, particularly those of Arnauld and Gassendi, contain acute and valuable criticisms. Descartes took exception to Gassendi’s contribution and wished not to have it published. He maintained that Gassendi quite misunderstood him, but that doesn’t seem true. It is true that Gassendi pokes fun at Descartes in addressing him first ‘O Soul’ and later, pretending to realize his mistake, ‘O Mind’, but no doubt the trouble was that Gassendi understood rather too well, fastening upon inconsequentialities in the argument and inconsistencies in the thought and finding, against both, formidable arguments. Inconsequentialities and inconsistencies there are, so much so that the work is a set of parts rested together to give the appearance of a construction, not fitted together really to make one. That did not prevent the Meditations having as great an influence on philosophical thought as any work from the day of its publication to our own, or prevent Descartes’ ideas from occupying the minds of philosophers ever since. Among Descartes’ scientific opinions were many that he did not know to be true. He held that nature abhorred a vacuum and he certainly did not know that to be true. Nature does not abhor a vacuum. He held that there were ice crystals in the upper atmosphere and that the white halo to be seen around the sun in some atmospheric conditions was formed by refraction of the sun’s light in those ice crystals, just as the rainbow is formed, men learnt from Descartes’ celebrated theory, so much deplored