Whatever is done without ostentation, and without the people being witnesses of it, is, in my opinion, most praiseworthy: not that the public eye should be entirely avoided, for good actions desire to be placed in the light; but notwithstanding this, the greatest theater for virtue is conscience.
As I give thought to the matter, I find four causes for the apparent misery of old age; first, it withdraws us from active accomplishments; second, it renders the body less powerful; third, it deprives us of almost all forms of enjoyment; fourth, it stands not far from death.
If you pursue good with labor, the labor passes away but the good remains; if you pursue evil with pleasure, the pleasure passes away and the evil remains.
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. . . ."
Sed nescio quo modo nihil tam absurde dici potest quod non dicatur ab aliquo philosphorum. (There is nothing so absurd but some philosopher has said it.)
When you wish to instruct, be brief; that men's [children's] minds take in quickly what you say, learn its lesson, and retain it faithfully. Every word that is unnecessary only pours over the side of a brimming mind.