The existence of a special term for a medical impostor is doubtless the result of the prevalence of the class thus named, but quackery and occult medicine though mutually overlapping, can by no means be held accountable for one another’s failings. Many forms of quackery proceed on the basis of superstitions or fanciful or exaggerated notions containing occult elements, but for the present purpose it is wise to limit attention to those in which this occult factor is distinctive; for medical quackery in its larger relations is neither modern nor occult. Occult healing takes its distinctive character from the theory underlying the practice rather than from the nature of the practice. It is not so much what is done as why it is done or pretended to be done or not done, that determines its occult character. A factor of prominence in modern occult healing is indeed one that in other forms characterized many of its predecessors and was rarely wholly absent from the connection between the procedure and the result; this is the mental factor, which may be called upon to give character to a theory of disease, or be utilized consciously or unconsciously as a curative principle. It is not implied that ‘mental medicine’ is necessarily and intrinsically occult, but only that the general trend of modern occult notions regarding disease may be best portrayed in certain typical forms of ‘psychic’ healing. The legitimate recognition of the importance of mental conditions in health and disease is one of the results of the union of modern psychology and modern medicine. An exaggerated and extravagant as well as pretentious and illogical over-statement and misstatement of this principle may properly be considered as occult.