But it may also be observed, more precisely, that even apart from strongly marked and conspicuous pathological conditions, which meanwhile assert themselves amongst the biological factors of crime, there is a very great number of these cases in which it cannot actually be said that the bio-psychical anomalies of the criminal are the effect of a physically and morally poisonous environment. In every family in which there are several children, we find (in spite of identical surroundings and conditions of a favourable kind, and suitable methods of training and education), individuals who differ intellectually from the cradle; we also find in the degree or in the kind of their talent, the same individuals also differ from their cradle in physical and moral constitution. And though the phenomenon may only be manifest in the less numerous cases of types which are markedly normal or abnormal, it is none the less true also in the more numerous cases of ordinary types. In this connection I may observe that physical and social conditions have a greater or a less influence in proportion as the physical and psychical constitution of the individual is more or less sound and vigorous. <p 61> The practical conclusion, therefore, of these general observations on the natural genesis of crime is this: Every crime is the result of individual physical and social conditions; and, since these conditions have a more or less dominant influence for various forms of crime, the most certain and profitable mode of defence which society can employ against criminality is of a twofold character, and both modes ought to be employed and brought into action simultaneously--in the first place, the amelioration of the social conditions, as a natural preventive of crime, in the nature of a substitute for punishment; and, secondly, measures of perpetual or temporary elimination of criminals, according as the influence of biological conditions in the evolution of crime is all but absolute, or more or less great, and more or less curable.