This tendency to alter under special conditions is common to human beings, in whom hunger, syphilis, trauma, and, still more frequently, morbid conditions inherited from insane, criminal, or diseased progenitors, or the abuse of nerve poisons, such as alcohol, tobacco, or morphine, cause various alterations, of which criminality--that is, a return to the characteristics peculiar to primitive savages--is in reality the least serious, because it represents a less advanced stage than other forms of cerebral alteration.
The ætiology of crime, therefore, mingles with that of all kinds of degeneration: rickets, deafness, monstrosity, hairiness, and cretinism, of which crime is only a variation. It has, however, always been regarded as a thing apart, owing to a general instinctive repugnance to admit that a phenomenon, whose extrinsications are so extensive and penetrate every fibre of social life, derives, in fact, from the same causes as socially insignificant forms like rickets, sterility, etc. But this repugnance is really only a sensory illusion, like many others of widely diverse nature.
=FIG. 23 ART PRODUCTION FROM PRISON (see page 135)=
=FIG. 24 A COMBAT BETWEEN BRIGANDS AND GENDARMES Designed by a Criminal (see page 135)=
_Pathological Origin of Crime._ The atavistic origin of crime is certainly one of the most important discoveries of criminal anthropology, but it is important only theoretically, since it merely explains the phenomenon. Anthropologists soon realised how necessary it was to supplement this discovery by that of the origin, or causes which call forth in certain individuals these atavistic or criminal instincts, for it is the immediate causes that constitute the practical nucleus of the problem and it is their removal that renders possible the cure of the disease.
These causes are divided into organic and external factors of crime: the former remote and deeply rooted, the latter momentary but frequently determining the criminal act, and both closely related and fused together.
Heredity is the principal organic cause of criminal tendencies. It may be divided into two classes: indirect heredity from a generically degenerate family with frequent cases of insanity, deafness, syphilis, epilepsy, and alcoholism among its members; direct heredity from criminal parentage.