In modern terms, the use of "euthanasia" in the context of Action T4 is seen to be a to disguise a program of genocide, in which people were killed on the grounds of "disabilities, religious beliefs, and discordant individual values". Compared to the discussions of euthanasia that emerged post-war, the Nazi program may have been worded in terms that appear similar to the modern use of "euthanasia", but there was no "mercy" and the patients were not necessarily terminally ill. Despite these differences, historian and euthanasia opponent Ian Dowbiggin writes that "the origins of Nazi euthanasia, like those of the American euthanasia movement, predate the Third Reich and were intertwined with the history of eugenics and Social Darwinism, and with efforts to discredit traditional morality and ethics."