law, that is, as a statement of the rules which determine the sequence of events throughout the world, it may be called Theoretical Magic: regarded as a set of precepts which human beings observe in order to compass their ends, it may be called Practical Magic. At the same time it is to be borne in mind that the primitive magician knows magic only on its practical side; he never analyses the mental processes on which his practice is based, never reflects on the abstract principles involved in his actions. With him, as with the vast majority of men, logic is implicit, not explicit: he reasons just as he digests his food in complete ignorance of the intellectual and physiological processes which are essential to the one operation and to the other. In short, to him magic is always an art, never a science; the very idea of science is lacking in his undeveloped mind. It is for the philosophic student to trace the train of thought which underlies the magician's practice; to draw out the few simple threads of which the tangled skein is composed; to disengage the abstract principles from their concrete applications; in short, to discern the spurious science behind the bastard art. If my analysis of the magician's logic is correct, its two great principles turn out to be merely two different misapplications of the association of ideas. Homoeopathic magic is founded on the association of ideas by similarity: contagious magic is founded on the association of ideas by contiguity. Homoeopathic magic commits the mistake of assuming that things which resemble each other are the same: contagious magic commits the mistake of assuming that things which have once been in contact with each other are always in contact. But in practice the two branches are often combined; or, to be more exact, while homoeopathic or imitative magic may be practised by itself, contagious magic will generally be found to involve an application of the homoeopathic or imitative principle. Thus generally stated the two things may be a little difficult to grasp, but they will readily become intelligible when they are illustrated by particular examples. Both trains of thought are in fact extremely simple and elementary. It could hardly be otherwise, since they are familiar in the concrete, though certainly not in the abstract, to the crude intelligence not only of the savage, but of ignorant and dull-witted people everywhere. Both branches of magic, the homoeopathic and the contagious, may conveniently be comprehended under the general name of Sympathetic Magic, since both assume that things act on each other at a distance through a secret sympathy, the impulse being transmitted from one to the other by means of what we may conceive as a kind of invisible ether, not unlike that which is postulated by modern science for a precisely similar purpose, namely, to explain how things can physically affect each other through a space which appears to be empty.