“Man is a biped without feathers.” — Plato

“Only man has ears that do not move.” — Pliny the Elder

“Drinking when we are not thirsty and making love all year round, madam; that is all there is to distinguish us from other animals.” — Pierre Beaumarchais

“Man is the only animal that can remain on friendly terms with the victims he intends to eat until he eats them.” — Samuel Butler

“Man is the only animal that laughs and weeps, for he is the only animal that is struck with the difference between what things are and what they ought to be.” — William Hazlitt

“Homo sapiens is the species that invents symbols in which to invest passion and authority, then forgets that symbols are inventions.” — Joyce Carol Oates

“The proper definition of a man is an animal that writes letters.” — Lewis Carroll