Nothing overshadows truth so much as authority.

A common error of ignorance is to maintain that what one does not know does not exist.

It was never shameful to learn from any teacher things that are useful to know.

No art, however minor, demands less than total dedication if you want to excel in it.

A man can do all things if he will.

As ability goes, so goes our fortune.

When I investigate and when I discover that the forces of the heavens and the planets are within ourselves, then truly I seem to be living among the gods.