The instincts with which every child is born furnish desires or cravings which must be dealt with in some fashion. They may be refined ("sublimated"), so far as is necessary and desirable, into energies of other sorts--as happens readily with the play-instinct--or they may remain as the source of perversions and inversions, and of cravings of new sorts substituted for those of the more primitive kinds under the pressure of a conventional civilization. The symptoms of the functional psychoneuroses represent, after a fashion, some of these distorted attempts to find a substitute for the imperative cravings born of the sexual instincts, and their form often depends, in part at least, on the peculiarities of the sexual life in infancy and early childhood. It is Freud's service to have investigated this inadequately chronicled period of existence with extraordinary acumen. In so doing he made it plain that the "perversions" and "inversions," which reappear later under such striking shapes, belong to the normal sexual life of the young child and are seen, in veiled forms, in almost every case of nervous illness. It cannot too often be repeated that these discoveries represent no fanciful deductions, but are the outcome of rigidly careful observations which any one who will sufficiently prepare himself can verify. Critics fret over the amount of "sexuality" that Freud finds evidence of in the histories of his patients, and assume that he puts it there. But such criticisms are evidences of misunderstandings and proofs of ignorance. Freud had learned that the amnesias of hypnosis and of hysteria were not absolute but relative and that in covering the lost memories, much more, of unexpected sort, was often found. Others, too, had gone as far as this, and stopped. But this investigator determined that nothing but the absolute impossibility of going further should make him cease from urging his patients into an inexorable scrutiny of the unconscious regions of their memories and thoughts, such as never had been made before. Every species of forgetfulness, even the forgetfulness of childhood's years, was made to yield its hidden stores of knowledge; dreams, even though apparently absurd, were found to be interpreters of a varied class of thoughts, active, although repressed as out of harmony with the selected life of consciousness; layer after layer, new sets of motives underlying motives were laid bare, and each patient's interest was strongly enlisted in the task of learning to know himself in order more truly and wisely to "sublimate" himself. Gradually other workers joined patiently in this laborious undertaking, which now stands, for those who have taken pains to comprehend it, as by far the most important movement in psychopathology.