To believe that man’s aggressiveness or territoriality is in the nature of the beast is to mistake some men for all men, contemporary society for all possible societies, and, by a remarkable transformation, to justify what is as what needs must be; social repression becomes a response to, rather than a cause of, human violence.

Leon Eisenberg (1922-2009) American psychiatrist and medical educator

“The Human Nature of Human Nature,” Science (14 Apr 1972)
    (Source)

Based on an address at Faculty of Medicine Day, McGill University Sesquicentennial Celebration, Montreal, Canada (1 Oct 1971).