René Descartes

Descartes was born in Touraine in 1596, educated by Jesuits, and trained in law before a career as a soldier and a gentleman of independent means. He spent much of his adult life in the Dutch Republic, moving often to protect his privacy.

He began philosophy again from the ground up. Doubting everything that could be doubted, he found one certainty — that he was thinking — and rebuilt from there a proof of God and of the external world. Discourse on the Method and Meditations on First Philosophy made the thinking self the starting point of modern philosophy.

He also joined algebra to geometry in coordinate mathematics and wrote on optics, the passions, and the body. Invited to Sweden to tutor Queen Christina, he died in Stockholm in 1650, in a climate he disliked.

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