The best plan is to profit by the folly of others.

Hope is a working-man's dream.

There is alas no law against incompetency; no striking example is made. They learn by our bodily jeopardy and make experiments until the death of the patients, and the doctor is the only person not punished for murder.

When a building is about to fall down, all the mice desert it.

This only is certain, that there is nothing certain.

The most valuable discoveries have found their origin in the most trivial accidents.

The ancients had little doubt about the true shape of the earth: "It's [the world's] shape has the rounded appearance of a perfect sphere. This is shown first of all by the name of 'orb' which is bestowed upon it by the general consent of mankind. ...Our eyesight also confirms this belief, because the firmament presents the aspect of a concave hemisphere equidistant in every direction, which would be impossible in the case of any other figure."