Descartes died in Sweden in 1650, a few weeks before his fifty-fourth birthday. He had spent most of his adult life in relative seclusion in what is now the Netherlands, while the Thirty Years' War waxed and waned around him. By 1667, when some French Cartesians arranged for the return of his remains to Paris, they had begun to publicize his works, to develop a characteristically Cartesian philosophy, and to be identified by critics as a ‘sect’. These early supporters included many philosophers who, apart from Nicolas Malebranche, are probably remembered today only as marginal figures in the history of Western thought. The name of Descartes, however, remains readily recognizable. He has entered the canon of Western philosophy so securely that that there is no longer any dispute about his significance.

Why was he important? Hardly for the phrase by which he is popularly remembered today, both by students of philosophy and by other readers: ‘I think, therefore I am’. This was not an original insight on his part, and it had a relatively minor role in his work. During the past century, Descartes has often been read as a metaphysician or, perhaps as frequently, as a philosopher who took seriously the arguments of sceptics. Alternatively, he is classified as a philosopher of subjectivity, as someone who outlined an internal map of the human mind and defended the irreducibility of conscious experiences.