Date: 1637

"Now a painter cannot represent all the different sides of a solid body equally well on his flat canvas, and so he chooses one of the principal ones, sets it facing the light, and shades the others so as to make them stand out only when viewed from the perspective of the chosen side. In just the ...

— Descartes, René (1596-1650)

Date: 1641

"I am not that structure of limbs which is called a human body. I am not even some thin vapour which permeates the limbs - a wind, fire, air, breath, or whatever I depict in my imagination; for these are things which I have supposed to be nothing."

— Descartes, René (1596-1650)

Date: 1641

The mind is a craftsman, the body his tool

— Descartes, René (1596-1650)

Date: 1644, 1647

"It must be realized that the human soul, while informing the entire body, nevertheless has its principal seat in the brain."

— Descartes, René (1596-1650)

Date: 1648

"Thus all common notions which are engraved in the mind have their origin in observation of things or in verbal instruction."

— Descartes, René (1596-1650)