1. The minute-to-minute effectiveness of the individual is maintained in part by mechanisms that inhibit potentially disruptive behavior.2. The term inhibition has been used as being much broader than suppression and repression, and as showing interrelationships not recognized when these latter terms are used-e.g., with such diverse matters as concentration and dissociation, the resumption of interrupted tasks, depressive reactions and manic states.3. The inhibition of potentially disruptive behavior is described in terms of an interplay between four main forces :—(a) The transitory inhibition exerted by the ongoing activity of the moment.(b) The intensification of inhibition through integration with stronger motivations.(c) The persistent inhibition exerted by basic concepts laid down by intense personal experience or by cultural indoctrination.(d) The inherent tendency of the individual to normalize his behavior; in this instance, to desensitize and integrate inhibited, intensified action tendencies by obtaining expression for them in reality, in fantasy, and in dreaming. This constitutes a denial of the assertion that the principle of wish fulfillment is of universal validity in explaining dream formation. Normalization is posited as a factor of major importance in psychodynamics.4. Stress has been laid on the fact that basic concepts exert their inhibitory powers in virtue of their degree of intensification, and not in virtue of their content. This has immense significance in understanding some of the origins of deviant behavior in terms of the divergence between intensely held cultural beliefs and the actualities of human activity. It has no less significance in illuminating the fact that beliefs and designs for behavior held to be noxious in one society may in another show no evidence of producing personality damage.