(_a_) Fundamental in Magic, wherever practised, is the idea of force, invisible and intangible, which can operate at a distance without any visible or tangible vehicle. The idea may have been formed (as we have seen) by analogy with several natural phenomena, such as the wind, radiant heat, sound, odour, and it is involved in a savage’s beliefs concerning the efficacy of charms, rites and spells. When a man dies, he lies speechless and motionless, no longer exerts his accustomed force in any way; but, if seen in a dream, he still speaks and acts, perhaps wrestles with the dreamer. Here, then, is that force which had deserted the body: it is visible and tangible in dreams only, or perhaps sometimes by twilight; or to gifted seers, or to dogs or pigs. The force exerted by the ghost or spirit is the same thing as force magical, except in one character: its action is capricious, depending on the good or ill will of the ghost or spirit; whereas purely magical forces have uniform tendencies. Magic, then, prepares and partially develops this idea of mysterious force, without which the appearance of a dead man in a dream, after his body has been buried or burnt, would have no reality or practical consequences for the living. Comparison with shadows and reflections could not lend reality to dreams; for they require the presence of the body, and themselves have no mechanical significance. Their association with the spirit or ghost probably follows the use of their names to describe the dream-imagery, which cannot at first have a name of its own. The same names being used for shadow or reflection and for spirit or dream-soul, the things are in some measure identified; and then the idea of force may be associated with shadows and reflections; so that the falling of a shadow upon a man may injure or slay him. Magic-force and spirit-force being the same thing, the question whether _mana_ is a magical or animistic notion is misleading. It will be conceived of by different tribes in one way or the other, according to the relative prevalence in one or the other tribe of the animistic or of the magical mode of explanation. (_b_) It is reasonable to expect that, as the ghost-theory spread, the magical force of things should sometimes be conceived of as spiritual; so that amulets and talismans would come to be regarded as owing their virtue either to a controlling spirit, or to an indwelling spirit peculiar to each: in the latter case the charm is a fetich. When a charm is thus considered, its efficacy is no longer expected to be uniform, but depends on the mood of the indwelling or controlling spirit. The fact that its efficacy, though formerly presumed to be uniform, never was so, favours the new interpretation; and this having been accepted, a cult (or a discipline) of the spirit is apt to follow. Thus the magician becomes a sorcerer or a priest.