I know what I do not know.

If measure and symmetry are absent from any composition in any degree, ruin awaits both the ingredients and the composition... Measure and symmetry are beauty and virtue the world over.

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

I am a fool, but I know I'm a fool and that makes me smarter than you.

Ordinary people seem not to realize that those who really apply themselves in the right way to philosophy are directly and of their own accord preparing themselves for dying and death.

No citizen has any right to be an amateur in the matter of physical training; it is part of his profession as a citizen to keep himself in good condition... [It is] a disgrace for a man to grow old without seeing the beauty and the strength of which his body is capable.

God desired to be the real maker of a real bed, not a particular maker of a particular bed, and therefore He created a bed which is essentially and by nature one only.