Traditionally, philosophers have set man apart from other animals because of his powers of reason. But man has another faculty which also distinguishes him from other animals - his ability to communicate by symbols. He is the one creature that reacts not only to his real physical environment but also to a symbolic environment of his own making. A hungry dog reacts to food by eating it. A man might, too, but just what he eats often depends on symbolic considerations. He may avoid some foods for fear of offending the deity; he may eat others for their reputed curative powers; he may even eat some, such as caviar, for status.

What all of this means is that man has an environment far different from that of other creatures. Most creatures live in just their physical environments. They receive stimuli, and they respond to them. They have no sense of past, no sense of future; as Kenneth Boulding reminds us, a dog has no idea that there were dogs on earth before he arrived and will be here after he has gone. But man, by creating a symbolic world, has given reality a dimension known only to the human species.

Between the mere stimulus and response of other creatures, he has erected a symbolic system that transforms the whole of human life and sets it apart from the life of all other animals. This distinctive mark of human life is not necessarily related to man's rationality (or to his irrationality, for that matter). It is a remarkable achievement that has taken man out of a merely physical universe and put him into a symbolic universe of language, art, and myth.

Man does not confront reality first-hand. Instead of always dealing with things themselves, as other animals do, he develops ideas about things. He so envelopes himself in linguistic forms, in artistic images, in mythical symbols, or in religious rites that he cannot see or know anything except through his symbolic system. As Epictetus said, "What disturbs and alarms man are not the things, but his opinions and fancies about the things."

Reality of course contains all the things which are given to man by his senses; but the framework and structure of reality are not something which man can touch or directly see. They are something intellectual, something he can perceive only indirectly through symbols. Animals react to outside stimuli either directly or not at all. Men, on the other hand, respond largely in a cerebral, invisible way. They produce images, notions, figments of all sorts, as symbols for ideas about things. A cat may cower under a porch during a thunderstorm; only a man would interpret the storm as a sign of a god's wrath. For man the symbol-maker, then, the world is mainly a pseudo-world, a web of symbols, of his own making.

Yet his pseudo-world is not sheer fantasy. Even the mythologies of man, like mathematics, language, and the formula E = me2, are his rational and practical efforts to deal with experience. They are attempts to organize his sensations and to build up around them symbolic systems that give meaning to his existence.

As a result, man's world is different from that of other animals, for it is both more and other than the physical stimuli which surround him. More important, it is precisely this symbol-making function that makes human communication and the social process possible.