In estimating the extent to which Mr. Buckle succeeded in consummating the labor which he undertook, we are not, therefore, to measure his results by the standard of the first, but by that of the second volume. It is not, then, the Science of History which he is striving to write; but only something 'which will interest the thinkers of this age, and something, perhaps, on which posterity may build.' His task, as thus abridged, was confined to the endeavor to establish the 'four leading propositions, which, according to my [his] view, are to be deemed the basis of the history of civilization;' that is, the basis of a Science of History. These propositions, given in a previous article, may be here repeated:
'1st. That the progress of mankind depends on the success with which the laws of phenomena are investigated, and on the extent to which a knowledge of those laws is diffused. 2d. That before such investigation can begin, a spirit of scepticism must arise, which, at first aiding the investigation, is afterward aided by it. 3d. That the discoveries thus made, increase the influence of intellectual truths, and diminish, relatively, not absolutely, the influence of moral truths; moral truths being more stationary than intellectual truths, and receiving fewer additions. 4th. That the great enemy of this movement, and therefore the great enemy of civilization, is the protective spirit; by which I mean the notion that society cannot prosper unless the affairs of life are watched over and protected at nearly every turn by the state and the church; the state teaching men what to do, and the church teaching them what they are to believe.'
In the first paper of this series, which was devoted to the examination of the third proposition as announced by Mr. Buckle and substantially affirmed by Professor Draper, together with the consideration of the fundamental Law of Human Progress, the error into which both of these distinguished writers had fallen in regard to the relative influence of moral and intellectual truths, was pointed out; as also the misconception under which they rested concerning the Law of Human Development. This misconception, it was then shown, arose from an incorrect understanding of the essential character of the Law itself, and could be traced, basically, to the same source whence sprang their mistake in reference to the comparative power of moral and mental forces. It is to a misapprehension, analogous to that which brought him into error concerning these two important points, that the radical defect of Mr. Buckle's first and fourth propositions is to be traced, as will be hereafter exhibited.