In the century from 1750 to 1850, to use a phrase of Whitehead, there was a change in the “climate of opinion” in the Western World. Men ventured upon new paths with new methods of investigation and new tests of reality. A score of epoch-making books appeared between Rousseau's Social Contract and Emile, 1762, on the one hand, and Comte's Positive Philosophy, 1853, and Spencer's earliest writings on the other. John Fiske said: “In their mental habits, in their methods of inquiry and in the data at their command, the men of the present day who have fully kept pace with the scientific movements are separated from the men whose education ended in 1830 by an immeasurably wider gulf than has ever divided one progressive generation of men from their predecessors.” This change of viewpoint and method of approach to reality involved both intellectual disintegration and theological reconstruction.