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)

Date: 1664

"Indeed, one may compare the nerves of the machine I am describing with the pipes in the works of these fountains, its muscles and tendons with the various devices and springs which serve to set them in motion, its animal spirits with the water which drives them, the heart with the source of the ...

— Descartes, René (1596-1650)

Date: 1664

"And finally, when a rational soul is present in this machine it will have its principal seat in the brain, and reside there like the fountain-keeper who must be stationed at the tanks to which the fountain's pipes return if he wants to produce, or prevent, or change their movements in some way."

— Descartes, René (1596-1650)

Date: 1664

"Now I maintain that when God unites a rational soul to this machine (in a way that I intend to explain later) he will place its principal seat in the brain, and will make its nature such that the soul will have different sensations corresponding to the different ways in which the entrances to th...

— Descartes, René (1596-1650)

Date: 1664

"But I shall content myself with telling you more about how the traces are imprinted on the internal part of the brain which is the seat of the memory."

— Descartes, René (1596-1650)

Date: 1664

"Thus they also trace figures in these gaps, which correspond to those of the objects. At first they do this less easily and perfectly than they do on gland H, but gradually they do it better and better, as their action becomes stronger and lasts longer, or is repeated more often. That is why the...

— Descartes, René (1596-1650)