Wonderful as all the described procedures seem to us, and closely as they may conform to the modern conception of superstition, at the time they originated they were considered as quite removed from that superstition with which we so closely identify them to-day. For the period which saw the above events was an era of exclusive theism, and for that reason divine sleep, divine feasts, the sacred performances, and all the other peculiar means which were employed to secure medical aid of the gods, were well-established features of religious worship. The stigma of superstition was not set upon them as yet. And this state of things naturally persisted so long as the theistic theory of life stood unchallenged. This absolute reign of theistic theory dominating human life through the above-described therapeutic ideas was followed by an epoch in which theism was forced to divide its authority with a powerful rival—namely, the physico-mechanical theory of life. The struggle between both these systems was ushered in, for the Hellenic as well as for the Occidental world of civilization, by the appearance of Ionian philosophy. Even in our own day this struggle is still going on in many minds. This much, at least, is certain: that superstition has always been especially active in medicine in areas of civilization where the theistic idea has gained the ascendency. The deadly struggle between theistic and physico-mechanical theories of life in the realm of medicine has found no place in the experience of Hellenic and Roman antiquity. The change in opinion was rather wrought by a gradual recession from the idea that the gods interfered with the proper course of man’s bodily functions. This conviction resulted from a progressive growth of his physico-mechanical knowledge, and became established at least as far as the thoughts and the opinions of the physicians were concerned. That the other classes, in particular the representatives of religion, did not so peaceably acquiesce in this mechanical conception of life we shall soon explain in Chapter III. It was different, however, with the art of healing itself. Even the Corpus Hippocraticum reveals to us a medicine which had been purified from all theistic admixtures, and from the publication of this work (_i.e._, from about the fifth century, B.C., up to the overthrow of the ancient period—_i.e._, until about the fifth or sixth century, A.D.) no further attempt to refer the cause of disease and the treatment of disease to the gods of the ancient heavens is noticed in medical works. On the contrary, that great efforts were made to look for the nature of disease in the mechanical conditions of the body is proven by a number of the most various medical doctrines. The extensive work of Galen, that antique canon of medicine, which dates back to the second century, A.D., disavows all theism and all theurgy, and relies solely upon physico-mechanical methods: observation, experiment, dissection.