The purpose of this essay is to analyse the eugenic pacifism of Giuseppe Sergi, one of Italy's most important anthropologists working at the turn of the nineteenth and twentieth centuries. Sergi's eugenic proposal, while accepting the long-contested idea of Weismann's germ plasm theory, preserves Lamarck's theory of the conditioning effect of the environment through the cautious use of Gregor Mendel's theory of recessiveness. Sergi, co-founder of the eugenic movement in Italy, thus affirmed the ‘salvific’ power of an upbringing that would assume the task of carrying forward to future generations the recessiveness of traits of violence, which would thereby assure humankind a prosperous future guaranteed by ‘competition between the races’, a competition that would no longer be on the battlefield but in the fields of industry, art and science.