Occam’s razor, also called law of parsimony, a principle stated by the Scholastic philosopher William of Ockham (1285–1347/49) that pluralitas non est ponenda sine necessitate, “plurality should not be posited without necessity.” The principle gives precedence to simplicity: of two competing theories, the simpler explanation of an entity is to be preferred. The principle is also expressed as “Entities are not to be multiplied beyond necessity.”

Hitler speaking in 1942 explaining why he brought the Holocaust into being: “Nature is cruel; therefore we are also entitled to be cruel. When I send the flower of German youth into the steel hail of the next war without feeling the slightest regret over the precious German blood that is being spilled, should I not also have the right to eliminate millions of an inferior race that multiplies like vermin?”

Source: Adolf Hitler, quoted in Hitler, by Joachim Fest, Vintage Books Edition, 1974, p. 679-680;