Anyone who suffers from an inheritable disease may be surgically sterilised if, in the judgement of medical science, it could be expected that his descendants will suffer from serious inherited mental or physical defects.
Over against all this, the völkisch concept of the world recognizes that the primordial racial elements are of the greatest significance for mankind. In principle, the State is looked upon only as a means to an end and this end is the conservation of the racial characteristics of mankind. Therefore on the völkisch principle we cannot admit that one race is equal to another. By recognizing that they are different, the völkisch concept separates mankind into races of superior and inferior quality.
The consequence of this racial purity, universally valid in Nature, is not only the sharp outward delimitation of the various races, but their uniform character in themselves. The fox is always a fox, the goose a goose, the tiger a tiger, etc., and the difference can lie at most in the varying measure of force, strength, intelligence, dexterity, endurance, etc., of the individual specimens. But you will never find a fox who in his inner attitude might, for example, show humanitarian tendencies toward geese, as similarly there is no cat with a friendly inclination toward mice.