Mithraism, probably brought back to Rome by soldiers who traveled to the east and perhaps related to astrology; only men were admitted as members. The cult believed in a powerful god who could move the heavens, it advanced the idea of fatalism and avowed a lack of personal responsibility for what happens in life. Bulls were slaughtered at the Mithraic ceremonies and in the caves where the followers met are found depictions of scorpions, dogs, snakes, and lots of blood.