When at last the whole vast list is compiled, and the scientist calls “Finish!” for lack of further time or interest, he may well have the impression that the ant’s behavior is no more than its automatic and involuntary reaction to its environment. It is attracted by this, repelled by that, kept alive by one condition, and destroyed by another. But let us suppose that he turns his attention to some other organism in the ant’s neighborhood—perhaps a housewife with a greasy kitchen—he will soon have to include that ant, and all its friends and relations, as something which determines her behavior! Wherever he turns his attention, he finds, instead of some positive, causal agent, a merely responsive hollow whose boundaries go this way and that according to outside pressures.