Oysters open completely when the moon is full; and when the crab sees one it throws a piece of stone or seaweed into it and the oyster cannot close again so that it serves the crab for meat. Such is the fate of him who opens his mouth too much and thereby puts himself at the mercy of the listener.

Great love is born of great knowledge of the thing that is loved, and if you do not know it, you can love it little or not at all.

Make yourself a master of perspective, then acquire perfect knowledge of the proportions of men and other animals.

If you find from your own experience that something is a fact and it contradicts what some authority has written down, then you must abandon the authority and base your reasoning on your own findings.

It is better to imitate ancient than modern work.

Mechanics is the paradise of the mathematical sciences because by means of it one comes to the fruits of mathematics.

Blinding ignorance does mislead us. O! Wretched mortals, open your eyes!