“From the human point of view a crime represents the satisfaction of a need of the criminal, like the satisfaction of any other need, and comes under the law of the struggle for existence. In fact, a need not satisfied constitutes a pain, and pain, whatever its nature be, first excites and then depresses and exhausts the functional power of the organism. The organism, under the influence of pain, loses a quantity of phosphates proportional to the intensity of the pain; the physiological equilibrium is broken, and some functions important for the internal economy are neutralized. The organism, because of the law of conservation, is called upon to relieve the pain. Often it can do this without injury to others; at other times it comes into collision with social interests, and in such a case falls into crime.” [232] After having spoken of the anatomical and physiological characteristics that have been observed in criminals, Dr. Battaglia comes to the investigation into the causes that produce crime. In examining the factors of crime we see, according to the author, that they consist of two great groups, first, criminogenous factors, and second, occasional factors. These last are important only when they are present with the first. Among the occasional factors are to be classed in the first place, age, meteorological occurrences, etc., in short, the influences to which the whole population are subjected. In the second place, sex, economic conditions, education, etc. i.e. influences which have a less universal sphere. However, none of the occasional factors can, by itself, cause a crime to arise. Otherwise a whole population would be criminal in the same way, since some factors, climate for instance, exercise their influence upon the whole population. In order to lead to crime these factors must exert their influence upon intellectual faculties especially disposed toward crime. The factors really criminogenous, are those which create certain physico-psychical conditions, from the complexus of which results the personal capacity for crime, such as the diseases and defects of development and nutrition, cranial and intracranial; improper education; psychical heredity; and atavistic reversions. “When these factors have prepared the mental condition, by making it different from that of all others, any opportunity whatever is a sufficient psychical factor, and a crime is committed. Therefore the criminogenous factors are those that have the real social importance, because they prepare inevitably for delinquency. “It is true, on the other hand, that any of the occasional factors, acting in a certain way, and with a certain intensity and persistency, can produce criminogenous factors, like education or alimentation.” [233]