_Objection to Stewart's Division._--The arrangement of Mr. Stewart is liable to this objection, that the principle of self-love, and also the moral faculty, which he classes by themselves as _rational_ principles, in distinction from the other emotions as _implanted_ or _instinctive_ principles, are as really implanted in our nature, as really constitutional or instinctive, as any other. Appetite, moreover, is but one form or class of desires; self-love is but another, _i. e._, the desire of our own happiness. _To Upham's Division._--The division of Mr. Upham is still more objectionable on the same ground. The _natural_ and the _moral_ sentiments, into which two great classes he divides the sensibilities, are distinct neither in fact nor in name; the moral sentiments, so called, are as really and truly _natural_, founded in our constitution, as are our desires and affections; nor is the term natural properly opposed to the term moral as designating distinct and opposite things. The terms instinctive and rational, which Mr. Stewart employs, though not free from objection, much more accurately express the distinction in view, could such a distinction be shown to exist. _Difference of ethical and psychological Inquiry._--In a work, the main object of which is to unfold the principles of ethical science, it may be desirable to single out from the other emotions, and place by themselves, the principle of self-love, together with the social principle and the moral sentiments, as having more direct reference to the moral character and conduct. In a strictly psychological treatise, however, in which the aim is simply to unfold, and arrange in their natural order, the phenomena of the human mind, such a principle of classification is evidently inadmissible. The different operations and emotions of the mind must be studied and arranged, not with reference to their _logical_ or _ethical_ distinctions, but solely their _psychological_ differences. Viewed in this light, the moral sentiments, so far as they are of the nature of feeling or sensibility at all, and not rather of intellectual perception, are simple emotions, and do not inherently differ from any other feelings of the same class. The satisfaction we feel in view of right, and the pain in view of wrong past conduct, differ from the pain and pleasure we derive from other sources, only as the _objects_ differ which call forth the feelings. They are essentially of the same class, the difference is specific rather than generic. They are modifications of the one generic principle of joy and sorrow, and differ from each other not so much as each differs from a _desire_, or an affection of love or hate.