One of the foundation-stones of modern philosophy, René Descartes' Meditations and Other Metaphysical Writings is translated from the Latin with an introduction by Desmond M. Clarke in Penguin Classics. Descartes was prepared to go to any lengths in his search for certainty - even to deny those things that seemed most self-evident. In his Meditations of 1641, and in the Objections and Replies that were included with the original publication, he set out to dismantle and then reconstruct the idea of the individual self and its existence. In doing so, Descartes developed a language of subjectivity that has lasted to this day, and he also took his first steps towards the view that would eventually be expressed in the epigram Cogito, ergo sum ('I think, therefore I am'), one of modern.