Intellectually speaking, the centuries since the fourteenth are the true middle ages. They mark the transitional period of mental habit, as the so-called medieval period represents the petrifaction, under changed outward conditions, of Greek ideas. The conscious articulation of genuinely modern tendencies has yet to come, and till it comes the ethic of our own life must remain undescribed. But the system of morals which has come nearest to the reflection of the movements of science, democracy, and commerce, is doubtless the utilitarian. Scientific, after the modern mode, it certainly would be. Newton’s influence dyes deep the moral thought of the eighteenth century. The arrangements of the solar system had been described in terms of a homogeneous matter and motion, worked by two opposed and compensating forces: all because a method of analysis, of generalization by analogy, and of mathematical deduction back to new empirical details had been followed. The imagination of the eighteenth century was a Newtonian imagination; and this no less in social than in physical matters. Hume proclaims that morals is about to become an experimental science. Just as, almost in our own day, Mill’s interest in a method for social science led him to reformulate the logic of experimental inquiry, so all the great men of the Enlightenment were in search for the organon of morals which should repeat the physical triumphs of Newton. Bentham notes that physics has had its Bacon and Newton; that morals has had its Bacon in Helvétius, but still awaits its Newton; and he leaves us in no doubt that at the moment of writing he was ready, modestly but firmly, to fill the waiting niche with its missing figure. The industrial movement furnished the concrete imagery for this ethical renovation. The utilitarians borrowed from Adam Smith the notion that through industrial exchange in a free society the individual pursuing his own good is led, under the guidance of the “invisible hand,” to promote the general good more effectually than if he had set out to do it. This idea was dressed out in the atomistic psychology which Hartley built out from Locke--and was returned at usurious rates to later economists. From the great French writers who had sought to justify and promote democratic individualism, came the conception that, since it is perverted political institutions which deprave individuals and bring them into hostility, nation against nation, class against class, individual against individual, the great political problem is such a reform of law and legislation, civil and criminal, of administration, and of education as will force the individual to find his own interests in pursuits conducing to the welfare of others.