Human variability, like the prolongation of human infancy to which John Fiske first directed attention, is an asset of inestimable value. Upon it the diversities of employments composing modern civilization have been developed. It is the trend of civilization to make the finer differences count. The guiding principle is that we all grow mentally, and perform more or less successfully, by virtue 1 Surveyed in a volume under that title by R. S. Ellis, D. Appleton & Company, New York, 1928. of the special abilities supported by the general level of our intelligence.

The nature of intelligence and of the variety of special aptitudes can but be referred to as conditioning the problem of the job; for it is far from so simple a matter as avoiding square pegs in round holes, or the reverse. Human aptitudes are of as many varieties as the geometric constituents of design. The industrial psychologist has appeared upon the scene, and personnel officers are attached to large corporations. Their service depends upon psychological findings.

That modern industry sets problems for the psychologist is a fact that need not detain us long. It may lead to a lack of proportion between intrinsic interest and the accident of economic worth, as is conspicuously true of the psychology of advertising - a "shop"specialty that happens to engage large financial investments. The true components of that equation are the set of desires and motives on the one side and the appeal that will direct them into the spending budget on the other. Advertising may add needless evidence to the familiar fact that a fool and his money are easily parted; and it may offer minor illustrations of the fluctuations and uncertainties of taste. The suspicion that much of it is economic waste is growing among such psychologically minded economists as Stuart Chase. As a topic it has far less intrinsic interest than the psychology of prestige or of persuasion, of which it forms a minor chapter.

By contrast, the psychology inherent in educational procedure or in industrial efficiency justifies the expenditure of time and technique in its study. Lost motion, whether in laying bricks, assembling a machine, or teaching children the rudiments of arithmetic, geography, history, manual arts, is a matter important enough to demand a proper analysis of its causes and a search for its remedies. The formation of proper manual habits is an indispensable step to right living in which the voice of psychology is claiming and receiving a hearing.

There has been slight attempt in this eclectic survey to apportion mention to importance, or to aim at any completeness of inclusion. Much has gone into the making of modern psychology that is omitted from this sketch. The purpose has been to convey a set of impressions that may compose into a picture - a motion picture - selecting significant moments in the story of how modern psychology came to be, together with excursions into characteristic scenes within its comprehensive domain.

To the same end a selection of general questions that have a material bearing on viewpoints in psychology may be added.

For one of these a place might have been found earlier in the exposition. It is equally appropriate in this connection, in further illustration of a problem of reflection persistent from Greek days. For the complement of the precept: "Man, know thyself," is the injunction:"Man, know thy world." How we come into relation with the stimulations to behavior, what it is that we react to, as well as how we react, are the problems of a psychology that has achieved the dignity of an independent name, not easily anglicized - "Gestalt psychology." The Gestalt is a concept of correction; its problem is the fundamental one of the terms in which the organism reacts to the environment; what it particularly corrects are the limitations and ignorings of a strict behaviorism. The convenient stenographic formula of the mechanism incorporated in a unit of behavior is stimulus and response, S-R. It is a label, not an explanation. As the strict behaviorist interprets it, it is a formula omitting the essential ingredient. It should read S-O-R - Stimulus + Organism + Response - and the clue to the relations of S and R lies wholly in the 0. It is the complete organism that determines what shall act as a stimulus and what form the response shall take. Because the clue to behavior resides in the organism, some psychologists have preferred to speak of this approach as organismic psychology. Why the behaviorist should choose to ignore the Hamlet of the play is not wholly clear; it certainly simplifies the plot, but it denatures the drama. It may be through dread of the later consequences, for Hamlet soliloquizes, which is a form of introspection and a manifestation of consciousness - both anathema to one adhering to the act as the sole datum. As Kohler, the leading exponent of Gestaltism suggests, the strict behaviorist (such as Weiss and Meyer) is determined to model the S-R reaction on a physical pattern, thus robbing it of its vitality."But between the two terms of the sensorimotor circuit there is more terra incognita than was on the map of Africa sixty years ago" and it is, as we have seen, to the successful exploration of that psycho-neurological province for sixty years that we owe the present rich knowledge of the psychic organism.

Gestaltism properly emphasizes that we react always to the total situation; it is not a stimulus, not a single condition, but a configuration that induces a reaction. The workman reacts to the whistle by going to work in one setting (time) and by quitting in another; and he doesn't react at all if it isn't his whistle. The phenomena are so complicated that it is often a problem to determine just what phase, what combination, what Gestalt sets off the reaction. The ingenious technique devised to this end is well illustrated in Kohler's "The Mentality of Apes" for Gestalt psychology has contributed importantly to the analysis of animal behavior. It is equally in line with the genetic sequence. For as we grow, we react to the (apparently) same situation more completely, ever to more complex Gestalts. This applies to emotional as well as to intellectual situations. Gestaltism1 thus supplies a significant correction of a fundamental problem. It is in accord with progressive psychology and, while making no claim to provide a program for the entire field, introduces a point of view comprehensively applicable.