"I began to think whether there might not be a motion as it were in a circle."

"The quantity of blood transmitted from the veins to the arteries, and so into the whole body, is so great that it must return to the heart."

"It is not by words, but by facts and arguments, that we must seek for truth."

"The greatest pleasure is to be found in the contemplation of truth."

"The motion of the blood is in a circle, and is in truth perpetual."