In the Hellenistic world, ‘mystical’ referred to “secret” religious rituals, specifically starting with the Eleusinian Mysteries in Ancient Greece. The mysteries were taken up in the same form in the Roman Empire and then morphed, as the dominant religion in the West shifted from the Olympians to the Way. This paper first focuses on the original meaning of the word, specifically as it refers to the Eleusinian Mysteries, the most significant Pan-Hellenic transcendence initiation ceremony aimed at accepting death and opening the consciousness into the superhuman understanding. The origins of the concept of mysteries, exploring in particular the Eleusinian mysteries, are briefly described, by investigating accounts from classical texts and arc...