Give me extension and motion and I will construct the universe.

We call infinite that thing whose limits we have not perceived, and so by that word we do not signify what we understand about a thing, but rather what we do not understand.

If I go for the alternative which is false, then obviously I shall be in error; if I take the other side, then it is by... chance that I arrive at the truth, and I shall still be at fault.... In this incorrect use of free will may be found the privation which constitutes the essence of error.

The only thing that I know, is that I know nothing

With me, everything turns into mathematics.

I am indeed amazed when I consider how weak my mind is and how prone to error.

There is a great difference between mind and body insomuch as body is by nature always divisible, and the mind is entirely indivisible.