Wisest is he who knows he knows not.

The understanding of mathematics is necessary for a sound grasp of ethics.

The same wind is blowing, and yet one of us may be cold and the other not.

True knowledge exists in knowing that you know nothing. And in knowing that you know nothing, that makes you the smartest of all.

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.

Nothing very new. By taking good care of yourselves you are of service to me and my family as well as yourselves, no matter what you do, even if you don't think so at present. But if you neglect yourselves and are unwilling to live, as though following tracks, in accordance with what we now say and have said in the past too, then no matter how much or how seriously you agree with me at present you will accomplish next to nothing.

I alone know I am wise because I alone know I know nothing.