We must live together as brothers or perish together as fools.

To live is not merely to breathe; it is to act; it is to make use of our organs, senses, faculties - of all those parts of ourselves which give us the feeling of existence

There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self.

Judge a man by his questions rather than by his answers.

All that we see or seem is but a dream within a dream.

To kill an error is as good a service as, and sometimes even better than, the establishing of a new truth or fact

There is nothing more uncommon than common sense.

A wise man can learn more from a foolish question than a fool can learn from a wise answer.

Intellectuals solve problems, geniuses prevent them.

Loneliness adds beauty to life. It puts a special burn on sunsets and makes night air smell better.

Good advice is always certain to be ignored, but that's no reason not to give it.

Blessed are they who hunger and thirst for righteousness for they shall be satisfied.

Each problem that I solved became a rule which served afterwards to solve other problems.

Never pick a fight with an ugly person, they've got nothing to lose.

When you learn, teach, when you get, give.

Most of what matters in our lives takes place in our absence.

To be one, to be united is a great thing. But to respect the right to be different is maybe even greater.

Intelligence is the ability to adapt to change.

Tomorrow hopes we have learned something from yesterday.

A friend to all is a friend to none

An understanding of the natural world is a source of not only great curiosity, but great fulfilment.