In reading the story of former opinion, it is of advantage to keep in mind the well-established facts regarding hypnotism, not alone for the sake of recognizing what is important and what unessential, what are the instructive and what the irrelevant facts and details, but also for the equal advantage of securing data for the interpretation of phenomena, which in the absence of present-day knowledge, and in the misleading accounts current at the time, naturally gave rise to extravagant forms of explanation. Our knowledge of insanity, hysteria, and trance-conditions, of the influence of the mind over the body, of the nature of illusion and hallucination, of prepossession and suggestion, shed a strong light upon religious ecstasy, upon demon-possession, upon cures by shrines and relics, or by the king's touch, upon the contagion of psychic epidemics, upon the action of magnetized tree or "mesmerized" water, upon the performances of "sensitives" and somnambulists, and the sensational scenes enacted about the "baquet." Our historical survey might accordingly include an account of the states of insensibility and of the potent power of suggestion, which occurred in connection with the religious observances in the practices of ancient civilizations, and have always formed, as they still form, a characteristic cult among primitive peoples. That such states, closely corresponding to the hypnotic trance, are induced for magical purposes among savages is more than probable; equally clear is it that interspersed through the venerable record of magic and witchcraft and ecstasy and exorcism and miraculous cures, are accounts of states, induced usually by religious fervor, which are strongly suggestive of some of the characteristics of the hypnotic condition. But in the interests of unity and brevity it will be best to limit attention to those ancestors of hypnotism, of whose methods and practices we have fairly definite information. More especially does the career of Mesmer supply the most favorable starting-point of the survey; yet some notice should be taken of those who preceded him in achieving reputation as healers of disease. II