Before revision: Plato's student Aristotle ( 384–322 BC) observed in his History of Animals that human beings are the only animals to walk upright and argued, in line with his teleological view of nature, that humans have buttocks and no tails in order to give them a cushy place to sit when they are tired of standing.
After revision: Plato's student Aristotle ( 384–322 BC) observed in his History of Animals that human beings are the only animals to walk upright and argued, in line with his teleological view of nature, that humans have buttocks and no tails in order to give them a soft place to sit when they are tired of standing.