As far removed as chemistry from alchemy, as astronomy from astrology, as the doctrine of the localization of function in the brain from phrenology, as ‘animal magnetism’ from hypnotic suggestion, are the crude and perverse notions of Christian Scientist or Metaphysical Healer removed from the rational application of the influence of the mind over the body. The growth and development of the occult forms an interesting problem in the psychology of belief. The motives that induce the will to believe in the several doctrines that have been passed in review are certainly not more easy to detect and to describe than would be the case in reference to the many other general problems--philosophical, scientific, religious, social, political or educational--on which the right to an opinion seems to be regarded as an inalienable heritage of humanity or at least of democracy. Professor James tells us that often “our faith is faith in some one else’s faith, and in the greatest matters this is most the case.” Certainly the waves of popularity of one cult and another reflect the potent influence of contagion in the formation of opinion and the direction of conduct. When we look upon the popular delusions of the past through the achromatic glasses which historical remoteness from present conditions enables us to adjust to our eyes, we marvel that humanity could have been so grossly misled, that obvious relations and fallacies could have been so stupidly overlooked, that worthless and prejudiced evidence could have been accepted as sound and significant. But the opinions to which we incline are all colored o’er with the deep tinge of emotional reality, which is the living expression of our interest in them or our inclination toward them. What they require is a more vigorous infusion of the pale cast of thought; for the problem of the occult and the temptations to belief which it holds out are such as can be met only by a vigorous and critical application of a scientific logic. As logical acumen predominates over superficial plausibility, as belief comes to be formed and evidence estimated according to its intrinsic value rather than according to its emotional acceptability, the propagandum of the occult will meet with greater resistance and aversion.