It is now recognised that, psychologically speaking, crime, insanity, and nervousness represent an imperfect adaptation to the environment in which the criminal, the lunatic, or the nervous person lives. This failure of adaptation may be due either to inborn lack of capacity to meet the requirements of the environment, or to lack of proper training. Not so many years ago it was the consensus of scientific opinion that in most cases of crime, insanity and nervousness the victim was hopelessly handicapped from the start by the nature of his being. There was much talk of "inherited criminality," "congenital brain defects," and "neuropathic inheritance." But observation and experiment have compelled an almost complete abandonment of this doctrine of fatal degeneration. To-day scientists largely hold that not more than 1 or 2 per cent. of criminals can be stigmatised as criminals by birth; that insanity is not inheritable, like eye-colour or hair-colour; and that nervousness is, at bottom, an acquired, rather than inherited, disorder. Accordingly, if crime, insanity, and nervousness are on the increase, it follows that faults of training, rather than innate and unescapable tendencies, are the responsible factors. More specifically, crime, insanity, and nervousness have increased because no adequate effort has been made, by appropriate training, to fit the individual to withstand the extra strain put upon him by the economic changes of the past half century. Still further, modern scientific research has discovered the specific training fault which, more than anything else, accounts for the failure in adaptation. Stated briefly, this fault consists in neglect to develop moral and emotional control during the first years of life. In the case of criminality it has been proved, by repeated experiment tried on a large scale,[10] that even the descendants of a long line of criminals, if carefully trained in early childhood, will lead upright lives. In the case of insanity, the discovery that the three principal causes of mental disease are excessive indulgence in alcohol, sexual indiscretions, and emotional stress, points directly to the importance of training, aimed at the development of moral control. But most impressive, as emphasising the need for beginning this training at an early age, is the evidence accumulated in the case of those functional maladies, hysteria, neurasthenia, and psychasthenia--evidence which we have already discussed in much detail in these pages.