He who fears dangers will not perish by them.

Fear arises sooner than anything else.

Affective gestures pointing to things near either in time or space should be made with the hand not very far from the body of the person pointing; and if these things are distant, the hand of the painter should be more extended and the face turned toward the person to whom he is addressing the demonstration.

I abhor the supreme folly of those who blame the disciples of nature in defiance of those masters who were themselves her pupils

Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory.

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

O time, swift robber of all created things, how many kings, how many nations hast thou undone, and how many changes of states and of various events have happened since the wondrous forms of this fish perished here in this cavernous and winding recess. Now destroyed by time thou liest patiently in this confined space with bones stripped and bare; serving as a support and prop for the superimposed mountain.