As with most eugenicists at the time, racial hygienists believed that the lack of eugenics would lead to rapid social degeneration, the decline of civilization by the spread of inferior characteristics.
During the last years of the 19th century, the German racial hygienists Alfred Ploetz and Wilhelm Schallmayer regarded certain people as inferior, and they opposed their ability to procreate.
Theories on racial hygiene led to an elaborate sterilization program, with the goal of eliminating what the Nazis regarded as diseases harmful to the human race.
Robert N. Proctor has shown that the list of illnesses which the law targeted included "feeblemindedness, schizophrenia, manic depression, epilepsy, Huntington's chorea, genetic blindness, and 'severe alcoholism.'"
The nurses and the staff who had assisted and performed the killings were then moved along with the gas chambers to the concentration camps, which were being built in order to be able to replicate the mass murders repeatedly.
[5] The precursors of this notion were earlier medical experiments which German doctors performed on African prisoners of war in concentration camps in Namibia during the Herero and Namaqua Genocide.
[7] The blueprint for Nazism's attitude toward other races was written by Erwin Baur, Fritz Lenz, and Eugen Fischer and published under the title Human Heredity Theory and Racial Hygiene (1936).