Date: 1641

"As I have just used it, 'nature' is simply a label which depends on my thought; it is quite extraneous to the things to which it is applied, and depends simply on my comparison between the idea of a sick man and a badly-made clock, and the idea of a healthy man and a well-made clock."

— Descartes, René (1596-1650)

Date: 1641

"Yet a clock constructed with wheels and weights observes all the laws of its nature just as closely when it is badly made and tells the wrong time as when it completely fulfils the wishes of the clockmaker. In the same way, I might consider the body of a man as a kind of machine equipped with an...

— Descartes, René (1596-1650)

Date: 1664

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

— 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

"That is to say, it is only the latter figures which should be taken to be the forms or images which the rational soul united to this machine will consider directly when it imagines some object or perceives it by the senses."

— Descartes, René (1596-1650)

Date: 1664

"I should like you to consider, after this, all the functions I have ascribed to this machine -- such as the digestion of food, the beating of the heart and arteries, the nourishment and growth of the limbs, respiration, waking and sleeping, the reception by the external sense organs of light, so...

— Descartes, René (1596-1650)