One of the standing obstacles in the path of personality research is the difficulty of describing the personality as a whole at any given cross-section of its development. In despair at the myriad difficulties of the task, academic psychology has long evaded the issue and concentrated its attention upon the minute exploration of detached aspects of the individual. The manuals of physiological psychology are full of painstaking accounts of how atomized aspects of the individual’s environment (the “stimuli”) modify the reactions of selected parts of the individual. What these manuals characteristically omit is a workable set of conceptions for the classification of the phenomena which are the objects of investigation in personality research. It is impossible to found a science of geology without inventing terms to distinguish plateaus, plains, mountains, and continental blocs, even though all these phenomena possess the common attributes of “matter.” What matters for the geologist is how the differences and not the likenesses come to pass. Much of the academic psychology, in its quest for precision and prestige, has quit studying the problem with which it is ostensibly engaged, and has substituted a minor field of physiology therefor. In so doing, it has lost any criterion for testing the relevance of the results of particular researches for the understanding of personality because it has no master concepts of personality. The psychopathologist has never been able to evade the necessity of summing up the personality as a whole because he has been compelled to make important decisions about the future of the personality as a whole. The psychiatrist must continually decide whether John B and Mary C will, if released from careful supervision, commit suicide or murder, or whether they will be dependable members of the community. Thus the clinician has found it imperative to search for signs which have high predictive value in relation to the major social adjustments of the individual.