Throughout the course of history man has been described as many different things. One of the most famous of these is Aristotle’s definition of man; Aristotle defined man as being a rational animal. According to this definition, rationality is what separates man from all other animals; it is what makes them unique. In order to prove this to be an accurate definition of man the definition of rational must first be understood. What makes man different from all other animals is mans ability to reason.
He is able to distinguish between what is right or wrong, good or evil and he makes a choice for the distinction made by the intellect. As a rational being, he is able to take responsibility for his actions because he knows out of reason and not instinct. Rational has more than one denotation and in order for man to be rational they must fit all or most of them. It also has to be proven that this definition is unique to man and that no other animal is rational. Aristotle’s definition of man is fairly accurate because man has some unique characteristics which makes them rational and are specific only to them.
Intelligence, the capability to understand and the ability to achieve goals through planned action are all characteristics unique to man which makes them rational. Aristotle's "Ethics" is a study of choice in action; how should man best live? For Aristotle, this has a social as well as individual aspect. Some virtues, like courage and generosity, he describes as "practical" virtues, because they relate to man's social nature. The truly balanced individual also pursues the "theoretical" virtues which are related to man as a rational being. Ultimate happiness lies in pursuit of wisdom for its own sake.