If I had engaged in politics, O men of Athens, I should have perished long ago, and done no good either to you or to myself.

If the whole world depends on today's youth, I can't see the world lasting another 100 years.

The more I learn, the less I realize I know.

All that I know is nothing - I'm not even sure of that.

What most counts is not merely to live, but to live right.

I am very conscious that I am not wise at all.

Knowledge is our ultimate good.