The time-worn question of conservatism as against change has evidently much in common with that of personality as against institutions. Innovation, that is, is bound up with the assertion of fresh personality against mechanism; and the arguments for and against it are the same as I have already suggested. Wherever there is vigor and constructive power in the individual there is likely to be discontent with the establishment. The young notoriously tend to innovation, and so do those of a bold and restless temperament at any age; the old, on the contrary, the quiet, the timid, are conservative. And so with whole peoples; in so far as they are enfeebled by climate or other causes they become inert and incapable of constructive change. What may not be quite so obvious, at least to those who have not read M. Tarde’s work on the Laws of Imitation,[141] is that innovation or the opposite may be a public habit, independently of differences in age or vigor. The attitude toward change is subject to the same sort of alteration as public opinion, or any other phase of the public mind. That a nation has moved for centuries in the deepest ruts of conservatism, like China or India, is no proof of a lack of natural vigor, but may mean only that the social type has matured and hardened in isolation, not encountering any influence pungent enough to pierce its shell and start a cycle of change. Thus it is now apparent that lack of incitement, not lack of capacity, was the cause of the backwardness of Japan, and there is little doubt that the same is true of China. Energy and suggestion are equally indispensable to all human achievement. In the absence of the latter the mind easily spends itself in minor activities, and there is no reason why this should not be true of a whole people and continue for centuries. Then, again, a spark may set it on fire and produce in a few years pregnant changes in the structure of society. The physical law of the persistence of energy in uniform quantity is a most illusive one to apply to human life. There is always a great deal more mental energy than is utilized, and the amount that is really productive depends chiefly on the urgency of suggestion. Indeed, the higher activities of the human mind are, in general, more like a series of somewhat fortuitous explosions than like the work of a uniform force.