This is why the processes of evolution and revolution--the only wholly social or collective processes--are the most efficacious, while partial rebellion and, still more, individual violence have only a very feeble power of social transformation; they are, moreover, anti-social and anti-human, because they re-awaken the primitive savage instincts, and because they deny, in the very _person_ whom they strike down, the principle with which they believe themselves animated--the principle of respect for human life and of solidarity. What is the use of hypnotizing oneself with phrases about "the propaganda of the deed" and "immediate action?" It is known that anarchists, individualists, "amorphists" and "libertarians" admit as a means of social transformation _individual violence_ which extends from homicide to theft or _estampage_, even among "companions;" and this is then merely a political coloring given to criminal instincts which must not be confounded with political fanaticism, which is a very different phenomenon, common to the extreme and romantic parties of all times. A scientific examination of each case by itself, with the aid of anthropology and psychology, alone can decide whether the perpetrator of such or such a deed of violence is a congenital criminal, a criminal through insanity, or a criminal through stress of political fanaticism. I have, in fact, always maintained, and I still maintain, that the "political criminal," whom some wish to class in a special category, does not constitute a peculiar anthropological variety, but that he can be placed under one or another of the anthropological categories of criminals of ordinary law, and particularly one of these three: the _born_ criminal having a congenital tendency to crime, the _insane_-criminal, the criminal by stress of fanatical _passion_. The history of the past and of these latter times afford us obvious illustrations of these several categories. In the Middle Ages religious beliefs filled the minds of all and colored the criminal or insane excesses of many of the unbalanced. A similar insanity was the efficient cause of the more or less hysterical "sanctity" of some of the saints. At the close of our century it is the politico-social questions which absorb (and with what overwhelming interest!) the universal consciousness--which is stimulated by that universal contagion created by journalism with its great sensationalism--and these are the questions which color the criminal or insane excesses of many of the unbalanced, or which are the determining causes of instances of fanaticism occurring in men who are thoroughly honorable, but afflicted with excessive sensibility. It is the most extreme form of these politico-social questions which, in each historical period, possesses the most intense suggestive power. In Italy sixty years ago it was _Mazzinnianisme_ or _Carbonarisme_; twenty years ago, it was _socialism_; now it is _anarchism_.