It is, then, only to conduct of the above kind that genuine moral worth can be ascribed. Its special mark is that it rejects and excludes the whole class of motives by which otherwise all human action is prompted: I mean the =self-interested= motives, using the word in its widest sense. Consequently the moral value of an act is lowered by the disclosure of an accessory selfish incentive; while it is entirely destroyed, if that incentive stood alone. The absence of all egoistic motives is thus the =Criterion= of an action of moral value. It may, no doubt, be objected that also acts of pure malice and cruelty are not selfish.[2] But it is manifest that the latter cannot be meant, since they are, in kind, the exact opposite of those now being considered. If, however, the definition be insisted on in its strict sense, then we may expressly except such actions, because of their essential token--the compassing of others' suffering. There is also another characteristic of conduct having real moral worth, which is entirely internal and therefore less obvious. I allude to the fact that it leaves behind a certain self-satisfaction which is called the approval of conscience: just as, on the other hand, injustice and unkindness, and still more malice and cruelty, involve a secret self-condemnation. Lastly, there is an external, secondary, and accidental sign that draws a clear line between the two classes. Acts of the former kind win the approval and respect of disinterested witnesses: those of the latter incur their disapproval and contempt. Those actions that bear the stamp of moral value, so determined, and admitted to be realities, constitute the phaenomenon that lies before us, and which we have to explain. We must accordingly search out what it is that moves men to such conduct. If we succeed in our investigation, we shall necessarily bring to light the true moral incentive; and, as it is upon this that all ethical science must depend, our problem will then be solved. [1] Comrades, true and loyal to our oath, care for my wife and child in remembrance of this. [2] Acts of malice and cruelty are so many gratifications of the ego, and are therefore, in a certain sense, selfish. _V_. Introduction, pp. xvi. and xvii.--(_Translator._) CHAPTER V. STATEMENT AND PROOF OF THE ONLY TRUE MORAL INCENTIVE.