Dare to know! Have the courage to use your own intelligence!

It is difficult for the isolated individual to work himself out of the immaturity which has become almost natural for him.

There is no virtue in penance and fasting which waste the body; they are only fanatical and monkish.

Give me matter, and I will construct a world out of it!

The science of mathematics presents the most brilliant example of how pure reason may successfully enlarge its domain without the aid of experience

Human beings are never to be treated as a means but always as ends.

Maturity is having the courage to use one's own intelligence!