On Mysteries by Marcellio Focino

In On Mysteries, Yamblicus responds to Porphyry that we are not forcing the gods to do anything with our Theurgic practices. Animal sacrifice is indeed inappropriate to the highest, purely immaterial gods, but it is effective for communing with the gods within the cosmos those heavenly divinities again. At one point, he sarcastically remarks that Porphyry is slipping away into philosophy, which makes philosophy sound distinctly second-rate in comparison to the sacred activities of the Theurgist. This aspect of on mysteries has alarmed some readers. E.R. Dodds called the work a manifesto of irrationalism.