Appearances often are deceiving.

Moderation in temper is always a virtue; but moderation in principle is always a vice.

Men become wise just as they become rich, more by what they save than by what they receive.

So many people have this idea: I want to achieve something great or be somebody great. And they neglect the step that leads to greatness. They don't honor this step at this moment because they have this idea of some future moment where they are going to be great.

Confidence is contagious. So is lack of confidence.

You can best serve civilization by being against what usually passes for it.

In anger we should refrain both from speech and action.

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

A good teacher protects his pupils from his own influence.

Science is organized knowledge. Wisdom is organized life.

It takes a lot of courage to show your dreams to someone else.

A mistake is always forgivable, rarely excusable and always unacceptable.

The essence of knowledge is, having it, to apply it; not having it, to confess your ignorance.

Experience is the only prophecy of wise men.

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

One must wait until the evening to see how splendid the day has been.

It is the mark of an educated mind to be able to entertain a thought without accepting it.

It is not the strength, but the duration, of great sentiments that makes great men.

The greatest minds are capable of the greatest vices as well as of the greatest virtues.

The smaller the mind, the greater the conceit.

If you do what you've always done, you'll get what you've always gotten.