Again it is customary to suppose that there is a single instinct of fear, or at most a few well-defined sub-species of it. In reality, when one is afraid the whole being reacts, and this entire responding organism is never twice the same. In fact, also, every reaction takes place in a different environment, and its meaning is never twice alike, since the difference in environment makes a difference in consequences. It is only mythology which sets up a single, identical psychic force which "causes" all the reactions of fear, a force beginning and ending in itself. It is true enough that in all cases we are able to identify certain more or less separable characteristic acts--muscular contractions, withdrawals, evasions, concealments. But in the latter words we have already brought in an environment. Such terms as withdrawal and concealment have no meaning except as attitudes toward objects. There is no such thing as an environment in general; there are specific changing objects and events. Hence the kind of evasion or running away or shrinking up which takes place is directly correlated with specific surrounding conditions. There is no one fear having diverse manifestations; there are as many qualitatively different fears as there are objects responded to and different consequences sensed and observed. Fear of the dark is different from fear of publicity, fear of the dentist from fear of ghosts, fear of conspicuous success from fear of humiliation, fear of a bat from fear of a bear. Cowardice, embarrassment, caution and reverence may all be regarded as forms of fear. They all have certain physical organic acts in common--those of organic shrinkage, gestures of hesitation and retreat. But each is qualitatively unique. Each is what it is in virtue of its total interactions or correlations with other acts and with the environing medium, with consequences. High explosives and the aeroplane have brought into being something new in conduct. There is no error in calling it fear. But there is error, even from a limited clinical standpoint, in permitting the classifying name to blot from view the difference between fear of bombs dropped from the sky and the fears which previously existed. The new fear is just as much and just as little original and native as a child's fear of a stranger.