It seems to me that most of the research work that has been done by me or in my laboratory is nearly as independent of introspection as work in physics or in zoology. The time of mental processes, the accuracy of perception and movement, the range of consciousness, fatigue and practise, the motor accompaniments of thought, memory, the association of ideas, the perception of space, color-vision, preferences, judgments, individual differences, the behavior of animals and of children, these and other topics I have investigated without requiring the slightest introspection on the part of the subject or undertaking such on my own part during the course of the experiments. It is usually no more necessary for the subject to be a psychologist than it is for the vivisected frog to be a physiologist.
James and Wundt agree in telling us that the experimental method is chiefly of use as a servant of introspection; indeed James says that there is no 'new psychology,' 'nothing but the old psychology which began in Locke's time, plus a little physiology of the brain and senses and theory of evolution, and a few refinements of introspective detail.' But our leaders in psychology have become our leaders by belying such partial statements. Although neither Wundt nor James has attempted any considerable experimental research, yet we look up to them as the founders of modern psychology. Wundt's original and laborious Physiologische Psychologie, the Leipzig laboratory and the Philosophische Studien have been in large measure the foundation stones of experimental psychology. The broad opportunistic treatment of James, instinct with genius and fearless of logical inconsistency, has been of immense service in freeing psychology from traditional fetters. I see no reason why psychology, at least the psychology of twenty years ago, may not be said to be the subjects treated in James's Principles of Psychology and Wundt's Physiologische Psychologic with such additional subjects as other psychologists have included or might have included in their treatises.
When the introspective purist says that the treatises of Wundt and James are potpouris of sciences, or that the kind of work that some of us have attempted to do belongs to physiology or to anthropometry or nowhere in particular, there is a natural temptation to reply that much of introspective and analytic psychology belongs to art rather than to science. Such things may be ingenious and interesting, like the personae of Bernard Shaw or the mermaids of Burne Jones, but we don't expect to meet them in the street. An attitude of this kind would, however, be as partial as that which it seeks to controvert. Let us take a broad outlook and be liberal in our appreciation; let us welcome variations and sports; if birth is given to monstrosities on occasion, we may be sure that they will not survive.
Any attempt at a priori limitation of the field of a science is futile.
