By the beginning of the Christian era, a change in secular and religious attitudes can be discerned. The rationalism that had guided the thinking of the elite in previous times waned, and the rise of skepticism and loss of direction led to a philosophical vacuum that stimulated a recourse to mystic intuition and divine mysteries. The area of the Roman Empire in which this process became primarily manifest was Egypt, where, after the conquest by Alexander the Great (in 332 BCE), the culture of Hellenism with its fusion of Greek and Eastern features was centered. The fashionable mystery beliefs subsumed under the names of Gnosticism and Hermetism exerted a strong attraction for practitioners of the occult sciences (astrology, magic, and medicine) as well as alchemy, the art of making gold: previously, men of science had by thought process and investigations obtained what they...