with his endeavor to explain natural processes in a natural manner. This attempt of the Milesian is the initiation of a rational scientific conception of natural manifestations, and the ancient theistic consideration of nature became superstition only in opposition to such a view. It follows, then, that what holds good with regard to the interpretation of natural manifestations in general holds good in medicine especially. Here, also, superstition came into question only when, besides the original theistic conception of the functions of the body and besides the metaphysical treatment of the sick, a valuation of the normal as well as of the morbid phenomena of the human organism came into vogue which took into account terrestrial causes. Not until this stage was reached did theism and theurgy lose their title and become superstition; until then they could claim fullest acceptance in medicine as thoroughly logical consequences of the prevailing theory of life. This took place, so far as Greek medicine was concerned, at about the end of the sixth century, B.C. The Corpus Hippocraticum already shows us Greek medicine as being purified from all theistic sophistications and only reckoning with natural causes. When this separation must have taken place for pre-Greek, Indian, Assyrian, and Egyptian culture can not be at present determined with certainty. For the Egyptian and Babylonico-Assyrian manuscripts, so far known, show an intimate admixture of true observation of nature with theistic speculations—_i.e._, a treatment of medicine which, altho it took account of physico-natural manifestations, was still deeply tinctured with superstition. According to what we have stated, medical superstition might be defined as follows: “Belief that the normal as well as the pathological manifestations of organic life may be explained and eventually treated, without consideration of their physical nature, by means of supernatural agencies.”