But this is not a static world, and there is no means of making it so. Curiosity, discovery, invention, all of these jeopardize by their nature the foundations of any society to which their results are denied admission. Toleration is therefore not merely desirable in itself, but also politically wise, because no other atmosphere of activity offers the assurance of peaceful adjustment. If power is held by a few, happiness will be confined to a few also. Every novelty will seem a challenge to that confinement; and it will always accrete about itself the wills of those who are excluded from a share in its benefits. For this world is not only dynamic; it is also diverse. The path to happiness is not a single one. Men are not willing to yield the insight of their experience to other men’s insight merely because they are commanded to do so. They must be persuaded by reason that one vision of desire is better than another vision, the experience commended to them must persuade and not enforce, if they are to accept its implications with a sense of contentment. This is, of course, a counsel of perfection. Men enjoy the exercise of power; no passion has a deeper hold upon human impulse. The willingness to admit the prospect of difference, the courage to see that one’s private truth is never commensurate with the whole truth, these are the rarest of human qualities. That is why the friends of liberty are always a minority in every society. That is why, also, the maintenance of liberty is a thing that has to be fought for afresh every day, lest an inert acceptance of some particular imposition make the field of action accessible to a general tyranny. For it is impossible to confine the area in which freedom may be permitted to some special and defined part of conduct. Those who have fought for the right to think freely in theology or the natural sciences are not less certainly the ancestors of political freedom. Without Bruno and Galileo there would have been neither Rousseau nor Voltaire.