[Footnote: This passage of Priestley occurs in his Essay on the First Principles of Government and on the Nature of Political, Civil, and Religious Liberty (1768, 2nd ed. 1771), pp. 2-4. His Lectures on History and General Policy appeared in 1788. Priestley was a strict utilitarian, who held that there is nothing intrinsically excellent in justice and veracity apart from their relation to happiness. The degree of public happiness is measured by the excellence of religion, science, government, laws, arts, commerce, conveniences of life, and especially by the degrees of personal security and personal liberty. In all these the ancients were inferior, and therefore they enjoyed less happiness. The present state of Europe is vastly preferable to what it was in any former period. And "the plan of this divine drama is opening more and more." In the future, Knowledge will increase and accumulate and diffuse itself to the lower ranks of society, who, by degrees, will find leisure for speculation; and looking beyond their immediate employment, they will consider the complex machine of society, and in time understand it better than those who now write about it. See his Lectures, pp. 371, 388 sqq., 528-53. The English thinker did not share all the views of his French masters. As a Unitarian, he regarded Christianity as a "great remedy of vice and ignorance," part of the divine plan; and he ascribed to government a lesser role than they in the improvement of humanity. He held, for instance, that the state should not interfere in education, arguing that this art was still in the experimental stage, and that the intervention of the civil power might stereotype a bad system. Not less significant, though less influential, than the writings of Priestley and Ferguson was the work of James Dunbar, Professor of Philosophy at Aberdeen, entitled Essays on the History of Mankind in Rude and Cultivated Ages (2nd ed., 1781). He conceived history as progressive, and inquired into the general causes which determine the gradual improvements of civilisation. He dealt at length with the effects of climate and local circumstances, but unlike the French philosophers did not ignore heredity. While he did not enter upon any discussion of future developments, he threw out incidentally the idea that the world may be united in a league of nations. Posterity, he wrote, "may contemplate, from a concurrence of various causes and events, some of which are hastening into light, the greater part, or even the whole habitable globe, divided among nations free and independent in all the interior functions of government, forming one political and commercial system" (p. 287). Dunbar's was an optimistic book, but his optimism was more cautious than Priestley's. These are his final words: