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

Those who are inspired by a model other than Nature, labor in vain.

As regards this vice, we read that the peacock is more guilty of it than any other animal. For it is always contemplating the beauty of its tail, which it spreads in the form of a wheel, and by its cries attracts to itself the gaze of the creatures that surround it. And this is the last vice to be conquered.

Thou, O God, dost sell us all good things at the price of labor.

How many emperors and how many princes have lived and died and no record of them remains, and they only sought to gain dominions and riches in order that their fame might be ever-lasting.

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

The eye transmits its own image through the air to all the objects which face it, and also receives them on its own surface, whence the "sensus communis" takes them and considers them.