Page:Popular Science Monthly Volume 47.djvu/867

Rh inquiries, and testing with her the inferences drawn from his experience with his first-born. There were two other infants under his observation at the time, though not so constantly and uninterruptedly as were his own children. In pursuing these studies Prof. Baldwin was led on to an enlargement of view concerning the mode and order of unfolding of mind in infancy, and the genesis of mind itself, and it is to this enlargement of view that we are indebted for the present work. It was while studying the child's imitations and their relation to volition that there came to him such a revelation concerning the function of imitation in the evolution of mind that he resolved to work out a theory of mental development embodying this new insight; and he soon saw that no consistent view of mental development in the individual could be reached without a doctrine of the race development of consciousness. With this conviction he undertook to make a synthesis of the biological theory of organic adaptation with the conception of infant development he had already reached. The work, he says, is a treatise upon this problem—an attempt to form a system of "genetic psychology." We can not give a fair account of Prof. Baldwin's theory in the limits of a book notice. But we will say, briefly, that he bases it upon the law of dynamogenesis, "which current psychology and biology agree in accepting as a well-established principle of the manifestations of organic and mental life. The principle of contractility, recognized in biology, simply states that all stimulations to living matter—from protoplasm to the highest vegetable and animal structures—if they take effect at all, tend to bring about movements or contractions in the mass of the organism. It is now also safely established as a phenomenon of consciousness that every sensation or incoming process tends to bring about action or outgoing process." It should be remarked here that the rise of hypnotism in late years has opened the way to an entirely new method of mental study. And it is now understood that "suggestion by idea, or through consciousness, must be recognized to be as fundamental a kind of motor stimulus as the direct excitation of a sense organ." Some idea of the importance of suggestion in modern psychology may be gained by noting the headings Prof. Baldwin has given to the sections in the long chapter upon this subject. They are (1) General Definition; (2) Physiological Suggestion; (3) Sensori-motor Suggestion; (4) Ideo-motor Suggestion; (5) Subconscious Adult Suggestion; (6) Inhibitory Suggestion; (7) Hypnotic Suggestion; (8) Law of Dynamogenesis.

In attempting to reach some kind of formula of dynamogenesis, Prof. Baldwin found the definitions of "suggestion" in the psychologies very conflicting, and he therefore adopted the most general description of suggestive reaction—i. e., "that it always issues in a movement more or less closely associated in earlier experience with the particular stimulus in question." This definition constitutes suggestion a phenomenon of habit; but many suggestions issue in movements not exactly like those before associated with these stimuli. Many of them beget new movements, by a kind of adaptation of the organism, which are an improvement upon those the organism has formerly accomplished. This kind of adaptation Prof. Baldwin names Accommodation, and one of the main subjects discussed in the book is this theory of accommodation. The chapter upon suggestion closes with these words: "So far as we have gone we have a right to use the principle of suggestion as a principle of dynamogenesis whenever we mean to say simply that action follows stimulus. But when we come to ask what kind of action follows in each case each special kind of stimulus, we have two possibilities before us. A habit may follow or an accommodation may follow. Which is it? And why is it one rather than the other? These are the questions of the theory of organic development to which our next chapters are devoted." These nine chapters are upon The Theory of Development; The Origin of Motor Attitudes and Expressions; Organic Imitation; Conscious Imitation (begun); The Origin of Memory and Association; Conscious Imitation (continued); The Origin of Thought and Emotion; Conscious Imitation (concluded);