And you say: "The statement is also completely relevant to a discussion of evolution. Evolution does assert that some are inferior to others. Evolution does assert that destruction of the weak leads to progress. So the statement is a central part of evolutionary theory and cannot be written off as a personal eccentricity of Darwin.
Whether or not Darwin's "social Darwinism" is amoral or evil or has merit has no effect on the historical truth or falsity of evolution. If Heisenberg were a Nazi, would that affect the truth of his uncertainty principle? Does the answer depend upon whether his political philosophy gave him insight into the physical world? Should philosemites accept Einstein's science, while anti-semites object that it is "Jewish science" (as actually happened). Did the failure of Marxist politics disprove Larmarckian evolution, or did the failure of Lamarckian techniques disprove themselves?
No, no, no. It is not amoral, it is immoral. It is indeed evil as we have seen from the results of its adoption in the 20th century. By any moral standard it is evil. As to whether this immorality makes it untrue, kindly discuss the points I make in post#208 .