[Ghost of Philip Marlowe]

Darwin was not so innocent of eugenics. His associates (and I believe a brother or cousin) were intimately involved with the budding eugenics movement in England. He knew what they were doing and approved of it.

[Tailgunner Joe]

"If reproduction as such is limited and the number of births decreased, then the natural struggle for existence, which only allows the strongest and healthiest to survive, will be replaced by the obvious desire to save at any cost even the weakest and sickest; thereby a progeny is produced, which must become ever more miserable, the longer this mocking of nature and its will persists." - Adolf Hitler

Hitler is obviously only arguing against birth control of aryans in this quote. While Malthus wanted to limit births in order that the poor wouldn't go hungry, Hitler hoped to cause their extinction and the speciation of a "master race" through competition with the unfit. While they had different goals, they both started from the same incorrect premises.