This book is not a book of philosophy, of history, or of political thought. It is a book that recounts an error of perception.

Behind the French Descartes lies a Breton Descartes. Not that this is unknown, but it goes unrecognised.

Recognising it would permit us a better acquaintance with the Descartes in question. Poet, scientist, adventurer, Descartes left a mark on his time as he left one on posterity. On every age, and maybe on ours in particular...

Descartes teaches us to think. He is a philosopher. And this is what we need. Philosophers. Thinking is not a luxury. When it is life that hangs in the balance. Descartes risked his own. What have we learned from it ?