What you can do, or think you can, begin it.

To act is easy, to think is hard; to act according to our thought is troublesome.

We know accurately only when we know little, with knowledge doubt increases.

Time is a strange thing. It is a whimsical tyrant, which in every century has a different face for all that one says and does.

Don't give us your doubts, gives us your certainties, for we have doubts enough of our own.

When you lose interest in anything, you also lose the memory for it.

Pity on the person who has become accustomed to seeing in necessity something arbitrary, who ascribes to the arbitrary some sort of reason, and even claims that following that sort of reason has religious value.