I read these words which are the sum of all moral philosophy, and which cut short all the disputes of the casuists: When in doubt if an action is good or bad, refrain.
I am convinced that everything has come down to us from the banks of the Ganges, astronomy, astrology, metempsychosis, etc. It does not behoove us, who were only savages and barbarians when these Indians and Chinese peoples were civilized and learned, to dispute their antiquity.
We admit, in geometry, not only infinite magnitudes, that is to say, magnitudes greater than any assignable magnitude, but infinite magnitudes infinitely greater, the one than the other. This astonishes our dimension of brains, which is only about six inches long, five broad, and six in depth, in the largest heads.
You will notice that in all disputes between Christians since the birth of the Church, Rome has always favored the doctrine which most completely subjugated the human mind and annihilated reason.
Descartes constructed as noble a road of science, from the point at which he found geometry to that to which he carried it, as Newton himself did after him. ... He carried this spirit of geometry and invention into optics, which under him became a completely new art.
Before receiving your instruction, I must tell you what happened to me one day. I had just had a closet built at the end of my garden. I heard a mole arguing with a cockchafer; 'Here's a fine structure,' said the mole, 'it must have been a very powerful mole who did this work.' 'You're joking,' said the cockchafer; 'it's a cockchafer full of genius who is the architect of this building.' From that moment I resolved never to argue.