I need hardly say that Hume has in the “Dialogue” from which I quote made use of a pleasant artifice to force on the reader’s attention the nature and difficulty of his problem: to find, namely, a common meaning for the words “virtue” and “vice,” by whomsoever used; in spite of the fact that nearly kindred civilizations will be the one confident it has found virtue, where the other is certain it has found vice. “How shall we pretend to fix a standard for judgments of this nature?” he finally puts the question. “By tracing matters,” he answers himself, “a little higher.... The Rhine flows north, the Rhone south; yet both spring from the _same_ mountain, and are also actuated in their opposite directions by the _same_ principle of gravity. The different inclinations of the ground on which they run cause all the differences of their courses.” And one by one with admirable skill, he takes up the virtues of our friend Alcheic, which to us are such conspicuous vices, to show that under the conditions of Greek life most had a quality in common with those perhaps directly opposite acts, which, under the conditions of our life we should commend, and that quality, which is the keynote of all Hume’s ethics, is “utility.” “It appears,” he puts it, “that there never was any quality recommended by anyone as a virtue or moral excellence, but on account of its being _useful_ or _agreeable_, to a man _himself_ or to _others_. For what other reason can ever be assigned for praise or approbation? Or where would be the sense of extolling a _good_ character or action, which at the same time is allowed to be _good for nothing_? All the differences, therefore, in morals may be reduced to this one general foundation, and may be accounted for by the different views which people take of these circumstances.” * * * * * Given Hume’s world-view, it is evident that the only ones whom we have a right to count in estimating the agreeable or disagreeable effects of our actions are such other sentient beings as experience reveals to us: to wit, our fellow humans and perhaps the higher animals. Moreover, the only period which we have a right to consider as containing a life’s measure of happiness and unhappiness is that which experience confirms to us: to wit, that bounded by birth and death.