The ultimate authority must always rest with the individual's own reason and critical analysis.

The absent are never without fault, nor the present without excuse.

Stupidity is a talent for misconception.

I hear and I forget. I see and I remember. I do and I understand.

Talent is God given. Be humble. Fame is man-given. Be grateful. Conceit is self-given. Be careful.

Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more

The only real laughter comes from despair.

Appearances often are deceiving.

A precedent embalms a principle.

Act enthusiastic and you will be enthusiastic

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

I write with experiences in mind, but I don't write about them, I write out of them.

Take care of the pieces well. The whole will take care of itself.

All the great things are simple, and many can be expressed in a single word: freedom; justice; honor; duty; mercy; hope.

Nothing is more intolerable than to have to admit to yourself your own errors.

Desire is poverty. Desire is the greatest impurity of the mind. Desire is the motive force for action. Desire in the mind is the real impurity. Even a spark of desire is a very great evil.

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

Don't raise your voice, improve your argument.

He who is cruel to animals becomes hard also in his dealings with men. We can judge the heart of a man by his treatment of animals.

Why fit in when you were born to stand out?

There is geometry in the humming of the strings. There is music in the spacing of the spheres.