Here is a painting he did about 1899 and entitled "Dark Thoughts."
We notice the thoughts are represented as feline bat-like creatures. Such a picture may well convey the world of thought, in the imagination of many Victorian thinkers. Notice the well lit lower spaces where people are accomplishing something, not just crouching vacantly. You could almost put this painting on a spectrum of representations of the modern spirit, preceding such works as Edvard Munch's "The Scream". The connection I am guessing at, is not one based on intellectual contact between thinkers, but a connection based on the realities these thinkers were all looking at. It might have seemed at the time that there were no intellectual alternatives to theories like the Darwinian survival of the fittest. I gotta stop
sampling PBR stuff. I can't think of anything funny to say about it.