In the development of indirect Magic, very many of its practices seem to involve one or other of the assumptions often called the principles of sympathetic Magic, namely, Mimesis and Participation: (1) that to operate upon a likeness or representation, or by analogy, affects the person, or object, or process imitated or represented as if it were directly assailed; and (2) that a part or appurtenance of any one may, in any magical undertaking, be substituted for the whole. Among savages these principles (as has already been said) are only latent forms of procedure, tacitly assumed, not formulated, and cannot have been the source of the practices, but must gradually have been established by them; but when notions of scientific arrangement came into vogue, they were discovered and explicitly stated by the early physicians and alchemists, in whose thoughts Magic and Science were not clearly differentiated. It has been supposed that these principles are natural consequences of the laws of the association (or reproduction) of ideas. According to the “law of similarity,” an idea of one thing often makes us think of another that resembles it: hence the thought of an enemy is supposed to make me think of an image of him, or the sight of his image makes me think of him. According to the law “of contiguity,” any two things having been seen or thought of together, thereafter the thought or sight of one of them makes me think of the other: hence the thought of an enemy makes me think of his footprint, or his footprint reminds me of him. Possibly. But must there not have been a long preparation of ideas before the thought of an enemy awakens in me these particular associations rather than many others? And if they should occur to me, how do the laws of association explain my astonishing belief that to put his image in the fire, or to thrust a thorn into his footprint, or to dig it up, carry it home and put it in the oven, will make him lame or afflict him with some wasting disease? There must be some system of ideas to determine these particular judgments. Some, again, suppose that savages cannot distinguish similarity from identity, part from whole; so that an image appears to them to be in earnest the same thing as a man, or his nail-parings the same as himself. Yet it is certain that in their work-a-day life they do make these distinctions, and that otherwise they could not get on at all. If, then, in certain cases, and in Magic (which is all that concerns us now), they act or speak as if unable to draw such distinctions, it must be from an acquired incapacity in that connection; just as in some cases they suffer from an acquired incapacity to recognise that their beliefs are contradicted by experience; that is to say, some fixed idea or dissociation prevents them from comparing the facts; though sometimes it may be merely that customary forms of speech hinder the expression of distinctions that really exist among their ideas.