Evolutionary theory quickly became the primary weapon for many efforts in social change. Reformers argued that the social and legal systems of Western Europe had been founded on antiquated notions of natural reason or Christian morality; and did not face squarely the irrevocable biology of human nature. Proposals for change might shock traditional ethics, but if they brought social procedure into harmony with human biology, we might establish the beginning of a rational and scientific order freed from ancient superstition and therefore, in the long run, humane in the literal sense.
The late nineteenth-century school of "criminal anthropology" pursued this argument relentlessly. Previous systems of criminal law relied on social and ethical ideas of justice, fairness, protection, and retribution. They made no attempt to judge the biology of criminals—to learn if any recognizable peculiarity of their heredity might predispose them to lawlessness. Previous systems studied the crime; modern science would study the criminal. "Criminal anthropology," wrote Sergi, "studies the delinquent in his natural place—that is to say, in the field of biology and pathology" (in Zimmern, 1898, p. 744).
Criminal anthropology had its roots in Italy where Cesare Lombroso, its founding father, published the first edition of L'uomo delinquente ("Criminal Man") in 1876. It spread widely and became one of the most important scientific and social movements of the late nineteenth century.
Lombroso argued that many criminals were born with an almost irrevocable predisposition to lawlessness. These born criminals could be recognized by definite physical signs; they were indeed "a well characterized anthropological variety" (Ferri to Fourth International Conference on Criminal Anthropology, 1896, quoted in Parmelee, 1912, p. 80). At this point Lombroso's argument takes a phyletic turn. The stigmata of the born criminal are not anomalous marks of disease or hereditary disorder; they are the atavistic features of an evolutionary past. The born criminal pursues his destructive ways because he is, literally, a savage in our midst—and we can recognize him because he carries the morphological signs of an apish past. Lombroso records his moment of truth:
In 1870 I was carrying on for several months researches in the prisons and asylums of Pavia upon cadavers and living persons, in order to determine upon substantial differences between the insane and criminals, without succeeding very well. Suddenly, the morning of a gloomy day in December, I found in the skull of a brigand a very long series of atavistic anomalies . . .