Galton and, still more fully, Fouillée have shown that the stagnation of the intellect of the Spanish people and the consequent decay of the power and glory of Spain have been chiefly due to the fact that the people of Spain ceased to produce those men of exceptional mental endowments, of intellectual energy and enterprise and independence of character, on whom primarily depend the power and prosperity of any nation and who are the most essential factors in the progress of the civilisation of any people, who in short are essential for the growth and endurance of national mind and character. And this was because during some centuries intellectual power, enterprise, and energy were steadily weeded out by a rigorous process of negative selection. In the first place, the Church, having attained enormous power, became in two ways a tremendous agency of negative selection. First, she made celibate priests of a very large proportion of all those whose natural bent was towards the things of the mind, multiplying monastic orders excessively. Secondly, by means of the Inquisition she destroyed with fire and sword or drove into exile through many generations all those who would not conform to her narrow creed, who combined intellectual power with independence and originality of spirit and a firm will. In addition she drove out all the Jews and all of Moorish origin. The second mode of negative selection, namely persecution exerted by the Church, was no doubt the more important, but the former also must have had a great effect. We are helped to realize the probable magnitude of the effect by reflection on facts set out in an article by Bishop Welldon[131]. He shows the great part played in English civilisation since the reformation by the sons of the English Clergy; including as they did a number of men of the highest achievements in all departments of our national life. If all those sons of clergy who have shown exceptional abilities, and all their descendants, had by the rule of celibacy been prevented from coming into existence, how disastrous would that have been for the English people, how much less successful and vigorous would the nation have become! A second powerful agency of negative selection was the immense colonial empire which Spain so rapidly acquired, especially her American conquests. The whole people was seized with the desire to enrich themselves with the gold of the New World, and was fascinated by the idea of imitating the romantic adventures of Cortes and Pizarro. Great numbers of the bolder and most capable spirits set out for the New World, and there either lost their lives or remained to mix their blood with that of the native Indians or the imported negroes. In either case their stock was lost to the mother country.