Now, those who effect a revolution ought to know whither they are leading the world. They have need of a social theory--and in point of fact the more thorough-going apostles of movement always have such a theory; and though, as we have remarked, the theory emerges from the practical needs which they feel, and is therefore apt to invest ideas of merely temporary value with the character of eternal truths, it is not on this account to be dismissed as of secondary importance. Once formed, it reacts upon the minds of its adherents, and gives direction and unity to their efforts. It becomes, in its turn, a real historic force, and the degree of its coherence and adequacy is matter, not merely of academic interest, but of practical moment. Moreover, the onward course of a movement is more clearly understood by appreciating the successive points of view which its thinkers and statesmen have occupied than by following the devious turnings of political events and the tangle of party controversy. The point of view naturally affects the whole method of handling problems, whether speculative or practical, and to the historian it serves as a centre around which ideas and policies that perhaps differ, and even conflict with one another, may be so grouped as to show their underlying affinities. Let us then seek to determine the principal points of view which the Liberal movement has occupied, and distinguish the main types of theory in which the passion for freedom has sought to express itself. The first of these types I will call the theory of the Natural Order.