Politeness and an affable address are our best introduction.

Nature has lent us life at interest, like money, and has fixed no day for its payment.

The authority of those who teach is often an obstacle to those who want to learn.

The following passage is one of those cited by Copernicus himself in his preface to De Revolutionibus: "The Syracusan Hicetas, as Theophrastus asserts, holds the view that the heaven, sun, moon, stars, and in short all of the things on high are stationary, and that nothing in the world is in motion except the earth, which by revolving and twisting round its axis with extreme velocity produces all the same results as would be produced if the earth were stationary and the heaven in motion. . . ."

What an ugly beast the ape, and how like us.

A true friend is a sort of second self.

You might as well take the sun out of the sky as friendship from life: for the immortal gods have given us nothing better or more delightful.