(2) Morality, however, makes not only for life, thus insuring its own perpetuation; it makes also for happiness. Arbitrary and tyrannous rules, cruel or needlessly prohibitive customs, engender restlessness, and are not stable. Such barbarous morals may long persist, propped by the power of the rulers, the superstitions of the people, and all the forces of conservatism; but sooner or later they breed rebellion and are cast aside. On the other hand, more rational codes promote peace and security, banish fear and hatred, and make for all the benefits of civilization. Such codes are in relatively more stable equilibrium and gradually tend to replace the others. All morality is, of course, in one aspect, a restraint upon desire, a check upon impulse; rebelliousness against its decrees will be perpetually recurrent until human nature itself is completely refashioned and men have no inordinate and dangerous desires. But while all codes of conduct are repressive at the moment of passion, they vary widely in the degree in which they satisfy or thwart man's deeper needs. Such institutions as the gladiatorial games of Rome, human sacrifice, or slavery, were fruitful of so much pain that they were bound in time to perish. In contrast with these cruel customs, the prohibitions of the Jewish law, the Ten Commandments, for example, were so humane, so productive of security and concord and a deep-rooted and lasting satisfaction, that they persisted and became the parent of much of our present day morality. An increasing part in this progress has been played by the conscious recognition of the advantages of code over code; but long before such explicit perception of advantage, the blind instincts and emotions of men were making for the gradual humanizing of morals, the selection of ideals and laws that make for human happiness. As civilization advances, the consideration of mere preservation counts for less, and that of happiness for more; the margin, the breathing space, for liberal interests, grows. Men become interested in causes for which they willingly risk their lives. But, except as these causes are fanatical, off the real track of moral progress, they make for human happiness. And the center of interest can never shift too far. For not only is premature death, an evil in itself, it precludes the cultivation of the humane pursuits that life might have allowed.