Time which diminishes all things increases understanding for the aging.

This excerpt is presented as reproduced by Copernicus in the preface to De Revolutionibus: "Some think that the earth remains at rest. But Philolaus the Pythagorean believes that, like the sun and moon, it revolves around the fire in an oblique circle. Heraclides of Pontus and Ecphantus the Pythagorean make the earth move, not in a progressive motion, but like a wheel in rotation from west to east around its own center."

He is a fool who leaves things close at hand to follow what is out of reach.

Nothing can produce so great a serenity of life as a mind free from guilt and kept untainted, not only from actions, but purposes that are wicked. By this means the soul will be not only unpolluted but also undisturbed. The fountain will run clear and unsullied.

It is not the most distinguished achievements that men's virtues or vices may be best discovered; but very often an action of small note. An casual remark or joke shall distinguish a person's real character more than the greatest sieges, or the most important battles.

Our nature holds so much envy and malice that our pleasure in our own advantages is not so great as our distress at others'.

The flatterer's object is to please in everything he does; whereas the true friend always does what is right, and so often gives pleasure, often pain, not wishing the latter, but not shunning it either, if he deems it best.