A structure of society, which has so evolved, should not be changed or tampered with. For a stratified society is the inevitable result of the laws of nature, the creation of natural forces, and not the product of human determination. For that reason, the structure of society should remain unchanged.

[With] this perception of society came the frightening observation that the inferior reproduced faster than the average while the superior reproduced slower than the average. These two tendencies together must worsen the quality of the genetic substance of the entire race progressively with each generation. The result must bring a degeneration (Entartung) of the race as a whole.⁵² This leads to a “debasement” (Verpöbelung) of the race and a fall of culture”.⁵³

The faster than average rate of reproduction of the inferior was a serious menace for Lenz 1932 and the following racial hygienists such as Ritter, Vogel and Finger in the Third Reich 1937.

(Source.)