The necessity in this case has certainly never been made manifest. Nevertheless the hypothesis may be admitted, inasmuch as neither the admission nor
in other words, unless it should appear that the phenomena observed cannot possibly inhere in any already admitted entity. Dugald Stewart's reasoning on this subject is curious, not because the argument, or that which it regards, is of the smallest interest or importance in itself, but as exhibiting the grossest misconception of the question that ever was palmed off upon an unwary reader. "Matter" must be owned to be the first in the field. We are conversant and intimate with it long before we know anything about "mind." When the immaterialist or mentalist, then, comes forward, it is his business either to displace matter entirely, substituting "mind" in the place of it; or else to rear up alongside of it, this, the antagonist entity for which he contends. If he attempts the former, he involves himself in a mere play of words. If he maintains that all the material phenomena are in fact mental phenomena, he does nothing but quibble. The author of the 'Natural History of Enthusiasm' has grievously mistaken the potency of this position. [See The physical (!) theory of another life, p. 14.] It is plain, we say, that in this case the immaterialist resolves himself into a mere innovator upon the ordinary language of men. He merely gives the name of "mental" to that which other people have chosen to call "material." The thing remains precisely what it was. If, on the other hand, he embraces the Latter of the alternatives offered to him, and, without supplanting matter, maintains "mind" to be co-ordinate with it, then he is bound to show a necessity for his "multiplication of entities." He is bound to prove that the phenomena with which he is dealing are incompatible with, or cannot possibly inhere in, the entity already in the field. But how is such a proof possible or even conceivable? Let us see what the immaterialist makes of it. It is his object to prove by reasoning that a certain series of phenomena cannot inhere in a certain admitted substance "matter," and must therefore be referred to a different substance "mind." Now all reasoning is either a priori or a posteriori. If he reasons in the former of these ways, he forms a priori such a conception of matter that it would involve a contradiction to suppose that the phenomena occasioning the dispute should inhere in it; he first of all fixes for himself a notion of matter, as of something with which certain phenomena are incompatible, something in which they cannot inhere; and then from this conception
