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: 1648

"Thus a man who is dressed can be regarded as a compound of a man and clothes. But with respect to the man, his being dressed is merely a mode, although clothes are substances. In the same way, in the case of a man, who is composed of a soul and a body, our author might be regarding the body as t...

— Descartes, René (1596-1650)

Date: 1658

"The soul seems to be like a little flame or a most attenuated kind of fire, which thrives or remains kindled while the animal lives, since if it no longer thrives or is put out, the animal dies."

— Gassendi, Pierre (1592-1655)

Date: 1664

"I suppose the body to be nothing but a statue or machine made of earth."

— Descartes, René (1596-1650)

Date: 1664

"The parts of the blood which penetrate as far as the brain serve not only to nourish and sustain its substance, but also and primarily to produce in it a certain very fine wind, or rather a very lively and pure flame, which is called the animal spirits."

— 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

"You can think of our machine's heart and arteries, which push the animal spirits into the cavities of its brain, as being like the bellows of an organ, which push air into the wind-chests; and you can think of external objects, which stimulate certain nerves and cause spirits contained in the ca...

— Descartes, René (1596-1650)

Date: 1664

"But the source which produces these spirits is usually so abundant that they enter these cavities in sufficient quantity to have the force to push out against the surrounding matter and make it expand, thus tightening all the tiny nerve-fibres which come from it (in the way that a moderate wind ...

— Descartes, René (1596-1650)