Age does not make us childish, as some say; it finds us true children.

You cannot dream yourself into a character; you must hammer and forge yourself one.

A person possessed with an idea cannot be reasoned with.

Philosophy goes no further than probabilities, and in every assertion keeps a doubt in reserve.

Wild animals never kill for sport. Man is the only one to whom the torture and death of his fellow-creatures is amusing in itself.

Instruction does not prevent waste of time or mistakes; and mistakes themselves are often the best teachers of all.