Caption:
Descartes: Diagram showing the ventricles of the brain (E) and pineal gland (H). A & B are fibers ending in walls of ventricles. Illustration from 1664. Rene Descartes (1596 -1650), French mathematician and philosopher, created co-ordinate geometry, a bridge between algebra and geometry, now known as Cartesian geometry. He is considered a founding father of modern philosophy, famous for his statement Cogito ergo sum (I think, therefore I am).