ABSTRACT
Man, Aristotle said, is a rational animal; and the possession of ‘reason’ is commonly thought to be what makes him distinctively a man. The term ‘reason’ is being used here in a large and loose sense, but reflection on it is a helpful way to begin. What does it mean? Not consciousness, of course; for no one can sensibly doubt that animals feel fear, hunger, pleasure, and pain. They even make mistakes, as when the dog drops his bone for the more inviting one in the water; and since only judgment can be mistaken, they must in some sense judge. And since judgment is thought, they think. Yet they do not think as we do. Our thought is somehow a different kind of affair; it is the thought of a rational being. And what may that mean? It means, I suggest, four things, which we commonly take together without distinguishing them or making them explicit.
