Instead of using medicine, better fast today.

There is no stronger test of a person's character than power and authority, exciting as they do every passion, and discovering every latent vice.

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."

Custom is almost a second nature.

Medicine to produce health must examine disease; and music, to create harmony must investigate discord.

Among real friends there is no rivalry or jealousy of one another, but they are satisfied and contented alike whether they are equal or one of them is superior.

Proper listening is the foundation of proper living.