To be ignorant of the lives of the most celebrated men of antiquity is to continue in a state of childhood all our days.

... being perpetually charmed by his familiar siren, that is, by his geometry, he neglected to eat and drink and took no care of his person; that he was often carried by force to the baths, and when there he would trace geometrical figures in the ashes of the fire, and with his finger draws lines upon his body when it was anointed with oil, being in a state of great ecstasy and divinely possessed by his science.

We ought to give our friend pain if it will benefit him, but not to the extent of breaking off our friendship; but just as we make use of some biting medicine that will save and preserve the life of the patient. And so the friend, like a musician, in bringing about an improvement to what is good and expedient, sometimes slackens the chords, sometimes tightens them, and is often pleasant, but always useful.

It is a hard matter, my fellow citizens, to argue with the belly, since it has no ears.

Know how to listen, and you will profit even from those who talk badly.

In words are seen the state of mind and character and disposition of the speaker.

Time is the wisest of all counselors.