Simon Iff Stories and Other Works, an excellent collection of occult detective tales by Aleister Crowley (yes, that Aleister Crowley).
They're rather unique. There are no supernatural elements whatsoever. Not even paranormal phenomena. These are all very human crimes. But Simon is a magus and he uses Crowley’s philosophy/religion to solve the crimes.
My review: https://vintagepopfictions.blogspot.com/2013/05/aleister-crowleys-simon-iff-stories-and.html