It is rather through impulse than through will that individual lives and the life of the community can derive the strength unity of a single direction. Will is of two kinds, of which one is directed outward and the other inward. The first, which is directed outward, is called into play by external obstacles, either the opposition of others or the technical difficulties of an undertaking. This kind of will is an expression of strong impulse or desire, whenever instant success is impossible; it exists in all whose life is vigorous, and only decays when their vital force is enfeebled. It is necessary to success in any difficult enterprise, and without it great achievement is very rare. But the will which is directed inward is only necessary in so far as there is an inner conflict of impulses or desires; a perfectly harmonious nature would have no occasion for inward will. Such perfect harmony is of course a scarcely realizable ideal: in all men impulses arise which are incompatible with their central purpose, and which must be checked if their life as a whole is not to be a failure. But this will happen least with those whose central impulses are strongest; and it will happen less often in a society which aims at freedom than in a society like ours, which is full of artificial incompatibilities created by antiquated institutions and a tyrannous public opinion. The power to exert inward will when the occasion arises must always be needed by those who wish their lives to embody some central purpose, but with better institutions the occasions when inward will is necessary might be made fewer and less important. This result is very much to be desired, because when will checks impulses which are only accidentally harmful, it diverts a force which might be spent on overcoming outward obstacles, and if the impulses checked are strong and serious, it actually diminishes the vital force available. A life full of inhibitions is likely not to remain a very vigorous life but to become listless and without zest. Impulse tends to die when it is constantly held in check, and if it does not die, it is apt to work underground, and issue in some form much worse than that in which it has been checked. For these reasons the necessity for using inward will ought to be avoided as much as possible, and consistency of action ought to spring rather from consistency of impulse than from control of impulse by will.