For the "categorical" theory of morality, see Kant's Theory of Ethics, trans. Abbott; F. H. Bradley, Ethical Studies; F. Paulsen, System of Ethics, book II, chap, V, secs. 3 and 4; Dewey and Tufts, Ethics, chap, XVI, sec. 2; H. Spencer, Data of Ethics, chap, III, sees. 12, 13. W. Fite, Introductory Study of Ethics, chap. X. H. Rashdall, Theory of Good and Evil, book I, chap. V. For the "according to nature" theory, see Epictetus and Marcus Aurelius, passim; Rousseau, Discourse on Science and Art, etc.; J. S. Mill, "Nature" in Three Essays on Religion; T.H. Huxley, Evolution and Ethics. T. N. Carver, The Religion Worth Having. For the "self-realization" theory, see T. H. Green, Prolegomena to Ethics; F. Paulsen, op. cit, esp. book II, chap, II, secs. 5-8; H. W. Wright, Self-Realization; J. S. Mackenzie, Manual of Ethics, 2d ed, chaps, VI and VII. W. Fite, op. cit, chap. XI. For theological ethics, see any of the older theological books. A brief comment may be found in H. Spencer's Data of Ethics, chap, IV, sec. 18. CHAPTER XIV THE WORTH OF MORALITY BEFORE proceeding to a more concrete unfolding of the difficulties and problems of morality, it will be well to formulate our theory in terms of modern biology, and then, finally, to answer those modern critics who reject not merely the rational explanation of morality but morality itself. Morality as the organization of human interests. The worth of morality is most commonly defended today, in biological terms, by describing it as a synthesis of human interests; it is valuable because it is what we really want and need. It does, indeed, forbid the carrying-out of any impulse which renders impossible greater goods; it flatly opposes that unrestrained satisfying of a part of our natures which we call self-indulgence, or of one nature at the expense of others which we call selfishness. But it stifles desire only for a greater ultimate good; it rejects that needless repression of a part of the self which we call asceticism, and an undue subordination of self to others. It is, then the organizing or harmonizing principle, subordinating the interests of each aspect of the self, and of the many conflicting selves, to the total welfare of the individual and of the community. As Plato pointed out, [Footnote: Republic, books. I-IV; e.g. (444): "Is not the creation of righteousness the creation of a natural order and government of one another in the parts of the soul, and the creation of unrighteousness the opposite?" and (352): "Is not unrighteousness equally suicidal when existing in an individual [as it is when it exists in the State], rendering him incapable of action because he is not at unity with himself, making him an enemy to himself?" and (443): "The righteous man does not permit the several elements within him to meddle with one another, or any of them to do the work of others; but he sets in order his own inner life, and is his own master, and at peace with himself; and when ...