impression should be made, that each of these qualifying terms designates a necessity of a peculiar kind, and if, as a consequence, the belief should be induced, that there are in reality so many different kinds of necessity, errors of the gravest character would arise--errors no more important, however, than actually do arise from the impression often induced, that moral necessity differs in kind from physical necessity. 5. I mention another very decisive advantage which the above definitions have in our present investigations. In the light of the terms Liberty and Necessity, as above defined, the two great schools in philosophy and theology are obliged to join issue directly upon the real question in difference between them, without the possibility on the part of either, of escaping under a fog of definitions about moral necessity, physical necessity, moral certainty, &c., and then claiming a victory over their opponents. These terms, as above defined, stand out with perfect clearness and distinctness to all reflecting minds. Every one must see, that the phenomena of the Will cannot but fall under the one or the other of the relations designated by these terms inasmuch as no third relation differing in _kind_ from both of these, is conceivable. The question therefore may be fairly put to every individual, without the possibility of misapprehension or evasion--Do you believe, whenever a man puts forth an act of Will, that in those circumstances, this one act only is possible, and that this act cannot but arise? In all prohibited acts, for example, do you believe that an individual, by the resistless providence of God, is placed in circumstances in which this one act only is possible, and this cannot but result, that in these identical circumstances, another and a different act is required of him, and that for not putting forth this last act, he is justly held as infinitely guilty in the sight of God, and of the moral universe? To these questions every one must give an affirmative or negative answer. If he gives the former, he holds the doctrine of Necessity, and must take that doctrine with all its consequences. If he gives the latter, he holds the doctrine of Liberty in the sense of the term as above defined. He must hold, that in the identical circumstances in which a given act of Will is put forth, another and different act might have been put forth; and that for this reason, in all prohibited acts, a moral agent is held justly responsible for different and opposite acts. Much is gained to the cause of truth, when, as in the present instance, the different schools are obliged to join issue directly upon the real question in difference between them, and that without the possibility of misapprehension or evasion in respect to the nature of that question. MOTIVE DEFINED.