[The negative or destructive phase of the Revolution stimulated the desire of Progress, and consequently the study of social phenomena] The strong reaction which was exercised upon the intellect by the first great shock of revolution was absolutely necessary to rouse and sustain our mental efforts in the search for a new system. For the greatest thinkers of the eighteenth century had been blinded to the true character of the new state by the effete remnants of the old. And the shock was especially necessary for the foundation of social science. For the basis of that science is the conception of human Progress, a conception which nothing but the Revolution could have brought forward into sufficient prominence. Social Order was regarded by the ancients as stationary: and its theory under this provisional aspect was admirably sketched out by the great Aristotle. In this respect the case of Sociology resembles that of Biology. In Biology statical conceptions were attained without the least knowledge of dynamical laws. Similarly, the social speculations of antiquity are entirely devoid of the conception of Progress. Their historical field was too narrow to indicate any continuous movement of Humanity. It was not till the Middle Ages that this movement became sufficiently manifest to inspire the feeling that we were tending towards a state of increased perfection. It was then seen by all that Catholicism was superior to Polytheism and Judaism; and this was afterwards confirmed by the corresponding political improvement produced by the substitution of Feudalism for Roman government. Confused as this first feeling of human Progress was, it was yet very intense and very largely diffused; though it lost much of its vitality in the theological and metaphysical discussions of later centuries. It is here that we must look if we would understand that ardour in the cause of Progress which is peculiar to the Western family of nations, and which has been strong enough to check many sophistical delusions, especially in the countries where the noble aspirations of the Middle Ages have been least impaired by the metaphysical theories of Protestantism or Deism.