And as to history, it cannot be said that the results of man's attempts at self-modeling appear to belie the liberty thus promised in his constitution. If he has retired his natural integument in favor of a device called clothing, capable of expressing endless nuances, not alone of status and wealth, but of temper and taste as well--conservatism or venturesomeness, solemnity, gaiety, profusion, color, dignity, carelessness or whim, he has not failed to fashion his inner self into equally various modes of character and custom. That is a hazardous refutation of socialism which consists in pointing out that its success would require a change in human nature. Under the spell of particular ideas monastic communities have flourished, in comparison with whose demands upon human nature the change required by socialism--so far as it calls for purer altruism and not pure economic folly--is trivial. To any one who asserts as a dogma that "human nature never changes," it is fair to reply, "It is human nature to change itself." When one reflects to what extent racial and national traits are manners of the mind, fixed by social rather than by physical heredity, while the bodily characters themselves may be due in no small measure to sexual choices at first experimental, then imitative, then habitual, one is not disposed to think lightly of the human capacity for self-modification. But it is still possible to be skeptical as to the depth and permanence of any changes which are genuinely voluntary. There are few maxims of conduct, and few laws so contrary to nature that they could not be put into momentary effect by individuals or by communities. Plato's Republic has never been fairly tried; but fragments of this and other Utopias have been common enough in history. No one presumes to limit what men can _attempt_; one only inquires what the silent forces are which determine what can _last_. What, to be explicit, is the possible future of measures dealing with divorce, with war, with political corruption, with prostitution, with superstition? Enthusiastic idealism is too precious an energy to be wasted if we can spare it false efforts by recognizing those permanent ingredients of our being indicated by the words pugnacity, greed, sex, fear. Machiavelli was not inclined to make little of what an unhampered ruler could do with his subjects; yet he saw in such passions as these a fixed limit to the power of the Prince. "It makes him hated above all things to be rapacious, and to be violator of the property and women of his subjects, from both of which he must abstain." And if Machiavelli's despotism meets its master in the undercurrents of human instinct, governments of less determined stripe, whether of states or of persons, would hardly do well to treat these ultimate data with less respect. 2. Human Nature, Folkways, and the Mores[66]