„Everything the Nazis did to Jews we are today practicing on animals. Our grandchildren will ask us one day: Where were you during the Holocaust of the animals? What did you do against these horrifying crimes? We won't be able to offer the same excuse for the second time, that we didn't know.“
— Helmut F. Kaplan
Quoted in Charles Patterson, Eternal Treblinka: Our Treatment of Animals and the Holocaust (New York: Lantern Books, 2002), p. 221.