The extraordinary complexity of behavior is sometimes held to be an added source of difficulty. Even though behavior may be lawful, it may be too complex to be dealt with in terms of law. Sir Oliver Lodge once asserted that "though an astronomer can calculate the orbit of a planet or comet or even a meteor, although a physicist
20 THE POSSIBILITY OF A SCIENCE OF HUMAN BEHAVIOR
can deal with the structure of atoms, and a chemist with their possible combinations, neither a biologist nor any scientific man can calculate the orbit of a common fly." This is a statement about the limitations of scientists or about their aspirations, not about the suitability of a subject matter. Even so, it is wrong. It may be said with some assurance that if no one has calculated the orbit of a fly, it is only because no one has been sufficiently interested in doing so. The tropistic movements of many insects are now fairly well understood, but the instrumentation needed to record the flight of a fly and to give an account of all the conditions affecting it would cost more than the importance of the subject justifies. There is, therefore, no reason to conclude, as, the author does, that "an incalculable element of self-determination thus makes its appearance quite low down the animal scale." Selfdetermination does not follow from complexity. Difficulty in calculating the orbit of the fly does not prove capriciousness, though it may make it impossible to prove anything else. The problems imposed by the complexity of a subject matter must be dealt with as they arise. Apparently hopeless cases often become manageable in time. It is only recently that any sort of lawful account of the weather has been possible. We often succeed in reducing complexity to a reasonable degree by simplifying conditions in the laboratory; but where this is impossible, a statistical analysis may be used to achieve an inferior, but in many ways acceptable, prediction. Certainly no one is prepared to say now what a science of behavior can or cannot accomplish eventually. Advance estimates of the limits of science have generally proved inaccurate. The issue is in the long run pragmatic: we cannot tell until we have tried