Although the nature and phenomena of hypnosis are still incompletely understood, there are a multitude of theories which attempt to explain its mechanism and results. The most that can be done at this time is to explore various views which are held by leading authorities at present. It can be said, however, that a majority of authorities agree that hypnosis ensues as a result of natural laws which have been incorporated in the human organism since the beginning of man as he is today. The older theories show almost as much disparity as today, but for the purposes of history it is probably necessary to enumerate only the "animal magnetism" of Frederick Anton Mesmer, and a mention of the "hysteria syndrome" of Jean Martin Charcot. Both names loom large in the history of hypnosis. Mesmer, an 18th century physician, believed that hypnosis occurred as a result of "vital fluids" drawn from a magnet or lodestone and which drew their unique qualities from the sun, moon and stars. Charcot, as well as Pierre Janet and others, was convinced that hypnosis was a form of hysteria and that only hysterics could be hypnotized. The former (Mesmer) thought further that metal became imbued by the solar qualities, and his system is also known as metalogy by which he meant the proper application of metals. Naturally, these theories have been largely abandoned today, although there are still a few who think that hypnosis is a form of hysteria. Some pioneers, notably Dr. William S. Kroger, a psychiatrically-oriented obstetrician and gynecologist who limits his practice to hypnotherapy, believe hypnosis is a conviction phenomenon which produces results that parallel the phenomena produced at Lourdes and other religious healing shrines. His formula is that faith, hope, belief and expectation, all catalyzed by the imagination, lead inevitably to hypnosis. He, like Emile Coue before him, is convinced that you cannot "will" yourself to be hypnotized, and that whenever the will and the imagination come into conflict, the imagination wins out. This fits in perfectly, of course, with the author's already discussed visual-imagery technique which requires a high degree of imagination. Dr. Kroger, like a few others, has proved to his own satisfaction that all hypnotic phenomena can be produced at a non-hypnotic level.