Now the implied belief that virtue can be defined otherwise than in terms of happiness (for else the proposition is that happiness is to be obtained by actions conducive to happiness) is allied to the Platonic belief that there is an ideal or absolute good, which gives to particular and relative goods their property of goodness; and an argument analogous to that which Aristotle uses against Plato's conception of good, may be used against his own conception of virtue. As with good so with virtue--it is not singular but plural: in Aristotle's own classification, virtue, when treated of at large, is transformed into virtues. Those which he calls virtues must be so called in consequence of some common character that is either intrinsic or extrinsic. We may class things together either because they are made alike by all having in themselves some peculiarity, as we do vertebrate animals because they all have vertebral columns; or we may class them together because of some community in their outer relations, as when we group saws, knives, mallets, harrows, under the head of tools. Are the virtues classed as such because of some intrinsic community of nature? Then there must be identifiable a common trait in all the cardinal virtues which Aristotle specifies, "Courage, Temperance, Liberality, Magnanimity, Magnificence, Meekness, Amiability or Friendliness, Truthfulness, Justice." What now is the trait possessed in common by Magnificence and Meekness? and if any such common trait can be disentangled, is it that which also constitutes the essential trait in Truthfulness? The answer must be, No. The virtues, then, not being classed as such because of an intrinsic community of character, must be classed as such because of something extrinsic; and this something can be nothing else than the happiness which Aristotle says consists in the practice of them. They are united by their common relation to this result; while they are not united by their inner natures.