The greatness of a life can only be estimated by the multitude of its actions. We should not count the years, it is our actions which constitute our life.

The most perfect society is that whose purpose is the universal and supreme happiness.

Why is there anything at all rather than nothing whatsoever?

Nihil est sine ratione. There is nothing without a reason.

Make me the the master of education, and I will undertake to change the world.

Music is a hidden arithmetic exercise of the soul, which does not know that it is counting.

The world is not a machine. Everything in it is force, life, thought.

He who hasn't tasted bitter things hasn't earned sweet things.

The present is saturated with the past and pregnant with the future.

Take what you need, do what you should, you will get what you want.

Virtue is the habit of acting according to wisdom.

Everything that is possible demands to exist.

It's easier to be original and foolish than original and wise.

Music is a secret and unconscious mathematical problem of the soul.

His second motto: Thou, nature, art my goddess; to thy laws my services are bound.

Less depends upon the choice of words than upon this, that their introduction shall be justified by pregnant theorems.

Arc, amplitude, and curvature sustain a similar relation to each other as time, motion, and velocity, or as volume, mass, and density.

The total number of Dirichlet's publications is not large: jewels are not weighed on a grocery scale.

Mathematics is the queen of the sciences.