Renaissance1596–1650 · French

René Descartes

Descartes sought to place knowledge on absolutely secure foundations by doubting everything that could possibly be doubted, then rebuilding from what survived. A mathematician as well as a philosopher — he invented analytic geometry — he brought a quest for mathematical certainty into metaphysics. His sharp distinction between mind and body set the agenda for centuries of debate.

Schools

RationalismCartesianism

Key concepts

Methodic DoubtCogito, ergo sumMind–Body Dualism

Core works

Meditations on First Philosophy
1641
Across six meditations, Descartes undertakes to demolish all his beliefs and accept only what is indubitable. He suspends trust in the senses, in the external world, even in mathematics, imagining a deceiving demon who falsifies his every thought. Yet one thing resists all doubt: that he is thinking. 'I think, therefore I am' becomes the first certainty. From the thinking self he argues outward — to the existence of God as a non-deceiver, and from there to the reliability of clear and distinct ideas and the existence of the material world. Along the way he argues that mind and body are distinct substances, a dualism that frames the modern problem of consciousness.
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Core works

Meditations on First Philosophy