Date: 1637

"I supposed, too, that in the beginning God did not place in this body any rational soul or any other thing to serve as a vegetative or sensitive soul, but rather that he kindled in its heart one of those fires without light which I had already explained, and whose nature I understood to be no di...

— 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: 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: w. 1628, published in 1684, 1701

"For the human mind has within it a sort of spark of the divine, in which the first seeds of useful ways of thinking are sown, seeds which, however neglected and stifled by studies which impede them, often bear fruit of their own accord."

— Descartes, René (1596-1650)