Darwin’s On the Origin of Species by Natural Selection, first published in 1859, was the key that secularists wished for to advance a rival comprehensive worldview based on non-Christian presuppositions. Darwinian evolution, considered the epitome of science, was seen as a way out of a world governed by a Creator who demanded ethical absolutes. But it’s become a Monkey’s Paw. Be careful what you wish for.
German scholar Ernst Haeckel (1834–1919) pushed the implications of Darwin’s theories to comprehensive limits. He was “a promoter of scientific racism and embraced the idea of Social Darwinism.” (Source) He believed that moral law was subject to biology. “Thousands, indeed millions of cells are sacrificed in order for a species to survive.” If this is true of biology, then it is equally true for society. “Haeckel’s use of Darwin’s theories was decisive in the intellectual history of his time. It united trends already developing in Germany of racism, imperialism, romanticism, nationalism, and anti-semitism.”