"Sleep is the absence of waking, just as death is the absence of life."

"Leeches should be kept a day before applying them. They should be squeezed to make them eject the contents of their stomachs."

"The knowledge of anything, since all things have causes, is not acquired or complete unless it is known by its causes."

"O what a lean cow! it is not fit to be killed: give it fodder until it gets fat."

"The mind is like a mirror; it gathers dust while it rests."