No human investigation can claim to be scientific if it doesn't pass the test of mathematical proof.

Strive to preserve your health; and in this you will better succeed in proportion as you keep clear of the physicians, for their drugs are a kind of alchemy concerning which there are no fewer books than there are medicines.

Not to appreciate life, all of life, is not to deserve it.

When you look at a wall spotted with stains...you may discover a resemblance to various landscapes, beautiful with mountains, rivers, rocks, trees. Or again, you may see battles and figures in action, or strange faces and costumes, and an endless variety of objects which you could reduce to complete and well-drawn figures.

Happy will they be who lend ear to the words of the dead.

Nothing strengthens authority so much as silence.

Threats alone, are the weapons of the threatened man.