Even the mind depends so much on temperament and the disposition of one's bodily organs that, if it is possible to find a way to make people generally more wise and more skilful than they have been in the past, I believe that we should look for it in medicine. It is true that medicine as it is currently practiced contains little of much use.

The first precept was never to accept a thing as true until I knew it as such without a single doubt.

I was convinced that our beliefs are based much more on custom and example than on any certain knowledge.

Desire awakens only to things that are thought possible.

For each of us there is a set limit to our intellectual powers which we cannot pass.

Wonder is the first of all the passions.

Omnia apud me mathematica fiunt.