This is the beginning of a New Yorker article purporting to explicate "the occult roots of modernism." The focus is Josephin Péladan (March 28, 1858 to June 27, 1918.) His play “Oedipus and the Sphinx” (1903), like his novels, is not available in English.
The thesis of the New Yorker article is that "mystics like Péladan prepared the ground for the modernist revolution of the early twentieth century."
"In the wake of two catastrophic world wars, mysticism lost its lustre."
And people forgot about Péladan.
The historical situation is misrepresented in this article we link to.
Peladan was not an influential part of the story, merely the product of forces difficult to discern beneath the public clamor. His career was a late efflorescence of the shock consequent to the advances of the natural sciences. The term "mysticism" has lost any denotative value in this context, and Pelandan helped ground into rubble such useful stepping stones. His garish ideas about psychic powers, for instance, make it harder to recover authentic possibilities.
His type however is still around and flourishing.