Descartes's 1641 split between res cogitans and res extensa — the pilot and the cockpit — that structured Western thought for four centuries and underwrote the foundational assumptions of artificial intelligence.
In the winter of 1619, René Descartes sat in a cold room and performed the most consequential act of philosophical imagination in Western history. Doubting everything, he concluded that one thing could not be doubted: the fact that he was doubting. A thinking thing existed. Cogito ergo sum. The formulation was elegant and catastrophic — dividing reality into thinking substance (mind) and extended substance (body, matter) that would never be satisfactorily reunited. The mind occupied the body the way a pilot occupies a cockpit, fundamentally separate from the apparatus it controlled. This picture structured psychology, neuroscience, and computer science for four centuries, underwriting the assumption that intelligence is substrate-independent — that the pilot does not need this particular cockpit. Merleau-Ponty's entire philosophy was a sustained, patient demolition of this assumption.
The Cartesian Divide
In The You On AI Field Guide
Descartes's Meditations (1641) formalized the divide that his Discourse on Method (1637) had sketched. The methodological move — radical doubt, followed by the recovery