"“the one considerable document that remains to us from the early period of human thought… when the spiritual and psychological knowledge of the race was concealed, for reasons now difficult to determine, in a veil of concrete and material figures and symbols which protected the sense from the profane and revealed it to the initiated. One of the leading principles of the mystics was the sacredness and secrecy of self-knowledge and the true knowledge of the Gods… Hence… (the mystics) clothed their language in words and images which had, equally, a spiritual sense for the elect, and a concrete sense for the mass of ordinary worshippers.”"