Life must be understood backward. But it must be lived forward.

Wonder is the beginning of wisdom.

The unexamined life is not worth living.

Knowing yourself is the beginning of all wisdom.

First say to yourself what you would be; and then do what you have to do.

Don't explain your philosophy. Embody it.

The happiness of your life depends upon the quality of your thoughts.

You have power over your mind, not outside events. Realize this, and you will find strength.

He who fears death will never do anything worthy of a man who is alive.

We suffer more often in imagination than in reality.