The Freudian psychology regards the mind of the adult as the outcome of a process of development the stages of which are within limits, orderly {72} and inevitable. The trend of this development in each individual is determined by forces which are capable of precise definition, and the final product of it is capable of yielding to expert examination clear evidence of the particular way in which these forces have acted and interacted during the developmental process. The mind of the adult, then, is like the body in bearing traces which betray to the skilled observer the events of its developmental history. Inconspicuous and apparently insignificant structures and peculiarities in the one no less than in the other prove to have had a meaning and a function in the past, however little significance their final form may seem to possess, and thus the psychologist is able to reconstruct the history of a given subject’s mind, although the most important stages of its development are hidden from direct observation as effectively as is the prenatal growth of the body. It seems to be a fundamental conception of the Freudian system that the development of the mind is accompanied and conditioned by mental conflict. The infant is regarded as being impelled by instinctive impulses which at first are solely egoistic. From the earliest moments of its contact with the world resistance to the full indulgence of these impulses is encountered. With the growth and intensification of such impulses, the resistance from external interference—the beginnings of social pressure—becomes more formidable, until at a quite unexpectedly early age a veritable condition of mental conflict is established—egoistic impulses fatally pressing for indulgence regardless of their acceptability to the environment, while environmental influences bear equally heavily against any indulgence unwelcome to surrounding standards of discipline, taste, or morality.