As true virtue is virtue which knows at what it is aiming, the knowledge of the nature of the highest aim becomes the chief question of ethics. What is the end of moral activity? Now we have just seen that that end must fall within, and not outside, the moral act. The end of goodness is the good. What, then, is the good? What is the supreme good, the _summum bonum_? A note of warning is necessary before we enter upon the details of this problem. Plato frequently speaks of all moral activity aiming at, and ending in, happiness. With modern phrases ringing in our ears, we might easily suppose this to mean that Plato is a utilitarian. The utilitarianism of Bentham and Mill is distinguished by the fact that it places the end of morality in happiness. Yet Plato was not a utilitarian, and would unhesitatingly have condemned the theory of Mill. He {221} would have found it identical in principle with the Sophistic doctrine that pleasure is the end of virtue. The only difference is that, whereas the Sophists identified virtue with the pleasure of the individual, Mill makes it the pleasure of the community. That act is right which leads to "the greatest happiness of the greatest number." In practice, of course, this makes a tremendous difference. But the principle is equally objectionable because, like the Sophistic theory, it founds morality upon mere feeling, instead of upon reason, and because it places the end of morality outside morality itself. Yet the formula of Mill, that the end of morals is happiness, seems the same as Plato's formula. What is the difference? The fact is that what Mill calls happiness Plato would have called pleasure. Pleasure is the satisfaction of one's desires, whether they are noble or ignoble. Then what is happiness? It can only be defined as the general harmonious well-being of life. Only that man is happy whose soul is in the state it ought to be in, only in fact the just, the good, and the moral man. Happiness has nothing to do with pleasure. If you could conceive an absolutely just and upright man, who was yet weighed down with every possible misery and disaster, in whose life pleasure had no part, such a man would still be absolutely happy. Happiness is, therefore, in Plato, merely another name for the _summum bonum_. In saying that the _summum bonum_ is happiness, Plato is not telling us anything about it. He is merely giving it a new name. And we are still left to enquire: what is the _summum bonum_? what is happiness?