To be curious about that which is not one's concern while still in ignorance of oneself is ridiculous.

When there is an income tax, the just man will pay more and the unjust less on the same amount of income.

Love is a grave mental illness.

Those who practice philosophy in the right way are in training for dying and they fear death least of all men.

For all good and evil, whether in the body or in human nature, originates ... in the soul, and overflows from thence, as from the head into the eyes.

The Earth is like one of those balls made of twelve pieces of skin.

We will be better men, braver and less idle, if we believe that one must search for the things one does not know, rather than if we believe that it is not possible to find out what we do not know and that we must not look for it.