Most subjects at universities are taught for no other purpose than that they may be re-taught when the students become teachers.

Be attentive, feel nothing in vain, measure and compare: this is the whole law of philosophy.

You can make a good living from soothsaying but not from truthsaying.

If all mankind were suddenly to practice honesty, many thousands of people would be sure to starve.

It is in the gift for employing all the vicissitudes of life to one's own advantage and to that of one's craft that a large part of genius consists.

Brevity: To say at once whatever is to be said.

Nothing puts a greater obstacle in the way of the progress of knowledge than thinking that one knows what one does not yet know.