Professor Skinner is an experimental psychologist, and his treatise on "Science and Human Behavior" is solidly based upon facts. But unfortunately the facts belong to so limited a class that when at last he ven­tures upon a generalization, his conclusions are as sweepingly unrealistic as those of the Victorian theorizer. Inevitably so; for Professor Skinner's indif­ference to what James calls the "physiological forces" is almost as complete as Herbert Spencer's. The genetic factors determining human behavior are dismissed by him in less than a page. There is no reference in his book to the findings of constitutional medicine, nor any hint of that constitutional psychol­ogy, in terms of which (and in terms of which alone, so far as I can judge) it might be possible to write a complete and realistic biography of an individual in relation to the relevant facts of his existence — his body, his temperament, his intellectual endowments, his immediate environment from moment to moment, his time, place and culture. A science of human behav­ior is like a science of motion in the abstract — neces­sary, but, by itself, wholly inadequate to the facts. Consider a dragonfly, a rocket and a breaking wave. All three of them illustrate the same fundamental laws of motion; but they illustrate these laws in different ways, and the differences are at least as important as the identities. By itself, a study of motion can tell us almost nothing about that which, in any given in­stance, is being moved. Similarly a study of behavior can, by itself, tell us almost nothing about the indi­vidual mind-body that, in any particular instance, is exhibiting the behavior. But to us who are mind-bodies, a knowledge of mind-bodies is of paramount importance. Moreover, we know by observation and experience that the differences between individual mind-bodies are enormously great, and that some mind-bodies can and do profoundly affect their social en­vironment. On this last point Mr. Bertrand Russell is in full agreement with William James — and with prac­tically everyone, I would add, except the proponents of Spencerian or Behavioristic scientism. In Russell's view the causes of historical change are of three kinds — economic change, political theory and important indi­viduals. "I do not believe," says Mr. Russell, "that any of these can be ignored, or wholly explained away as the effect of causes of another kind." Thus, if Bis­marck and Lenin had died in infancy, our world would be very different from what, thanks in part to Bis­marck and Lenin, it now is. "History is not yet a science, and can only be made to seem scientific by falsifications and omissions." In real life, life as it is lived from day to day, the individual can never be explained away. It is only in theory that his con­tributions appear to approach zero; in practice they are all-important. When a piece of work gets done in the world, who actually does it? Whose eyes and ears do the perceiving, whose cortex does the thinking, who has the feelings that motivate, the will that overcomes obstacles? Certainly not the social environment; for a group is not an organism, but only a blind uncon­scious organization. Everything that is done within a society is done by individuals. These individuals are, of course, profoundly influenced by the local culture, the taboos and moralities, the information and misin­formation handed down from the past and preserved in a body of spoken traditions or written literature; but whatever each individual takes from society (or, to be more accurate, whatever he takes from other indi­viduals associated in groups, or from the symbolic rec­ords compiled by other individuals, living or dead) will be used by him in his own unique way — with his special senses, his biochemical make-up, his physique and temperament, and nobody else's. No amount of scientific explanation, however comprehensive, can ex­plain away these self-evident facts. And let us remem­ber that Professor Skinner's scientific portrait of man as the product of the social environment is not the only scientific portrait. There are other, more realistic likenesses. Consider, for example, Professor Roger Wil­liams' portrait. What he paints is not behavior in the abstract, but mind-bodies behaving-mind-bodies that are the products partly of the environment they share with other mind-bodies, partly of their own private heredity. In The Human Frontier and Free but Une­qual Professor Williams has expatiated, with a wealth of detailed evidence, on those innate differences between individuals, for which Dr. Watson could find no support and whose importance, in Professor Skinner's eyes, approaches zero. Among animals, biological varia­bility within a given species becomes more and more conspicuous as we move up the evolutionary scale. This biological variability is highest in man, and hu­man beings display a greater degree of biochemical, structural and temperamental diversity than do the members of any other species. This is a plain observa­ble fact. But what I have called the Will to Order, the desire to impose a comprehensible uniformity upon the bewildering manifoldness of things and events, has led many people to ignore this fact. They have minimized biological uniqueness and have concentrated all their attention upon the simpler and, in the present state of knowledge, more understandable environmental fac­tors involved in human behavior. "As a result of this environmentally centered thinking and investigation," writes Professor Williams, "the doctrine of the essen­tial uniformity of human infants has been widely ac­cepted and is held by a great body of social psychol­ogists, sociologists, social anthropologists, and many others, including historians, economists, education­alists, legal scholars and men in public life. This doctrine has been incorporated into the prevailing mode of thought of many who have had to do with shaping educational and governmental policies and is often accepted unquestioningly by those who do little critical thinking of their own."