Some, again, who are substantially, at least in all important respects, on our side of the question, have not been satisfied with showing that the two sets of properties are generically different, and that the same reason exists for ascribing the one to a distinct substantive being called "mind," as for ascribing the other to a substantive being called "matter." They have been anxious to advance a step further; and to show that the two sets of properties are _mutually exclusive_, and that they could not possibly _coexist_ in the same subject. This is the declared object of Baxter's Work on the Soul, which professes to prove that the only power belonging to "matter," namely, its _vis inertiae_, or resistance to any change in its present state, is inconsistent with its possession of any active power. It is not held sufficient to show that the properties are generically different, and that the substances in which these properties inhere may and should be designated by distinct names, as matter and spirit, soul and body; but it must be further proved that they are so heterogeneous and inconsistent as to be mutually exclusive, and incapable of coexisting in the same substance. To a certain extent, we think this mode of reasoning may be admitted. We do not conceive that "vis inertiae" is the only property belonging to matter, or that it is necessarily exclusive of attraction and repulsion, and the other powers which may belong to its specific varieties; but we do conceive that the "vis inertiae" of mere matter is utterly inconsistent with the self-activity, the self-moving power, which belongs to "mind:" and we are confirmed in this conviction by the anxiety which our opponents have evinced to explain the phenomena of mind by purely mechanical laws, and to establish a system, not of _moral_, but of _material_ necessity, in opposition to the doctrine of man's spontaneity and freedom. We are further of opinion, that _extension_ cannot be predicated of "mind," without also being predicated of "thought;" and that to ascribe it to either would lead to ridiculous absurdities, such as have been noted, and perhaps caricatured, by Dr. Thomas Brown. We think, too, that the unity and continuity of consciousness, with the intimate sense of personal identity, that belongs to all rational and responsible beings, are utterly irreconcilable with the continual flux and mutation that are incident to matter, and that they cannot be accounted for without the supposition of a distinct substance, existing the same throughout all the changes that occur in the material receptacle in which it dwells. To this extent we think that the argument is alike legitimate and valid; but when it goes beyond this, and attempts either to divest matter of all active properties, or to demonstrate that, in the very nature of things, sensation and thought could not possibly be annexed to a material substance, we think that it advances beyond the real exigencies