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.

The third and culminating cause was the career of military aggression pursued by Charles V; this completed the extermination of the aristocracy of ability and finally plunged Spain into an intellectual torpor which has persisted ever since and from which she can only be raised up by a succession of men of first-rate intellect and character: men such as she seems incapable of producing, because her people has thus been drained of all its most valuable elements, because her eugenic stocks have been exterminated.

The fall of Spain illustrates not only the operation of internal social selection affecting certain mental qualities; it illustrates also once more, even more clearly than the fall of Greece, the fact that the civilisation of a people and its power and position in the world depend altogether upon its intellectual aristocracy, and that the fall of a people from a high place necessarily follows the failure to continue to produce such an aristocracy.

In the civilised nations of the modern world, the most important kind of selection at work at the present time is what is distinguished as ‘economic selection’ working in conjunction with the formation of the social classes. It has no doubt operated at various times among other civilised peoples, but never so strongly and universally as at present.

All the leading civilised nations have passed, in the eighteenth and earlier part of the nineteenth centuries, through a period in which the discoveries of science have enormously increased the productive powers of man and man’s control over, and power of resistance to, the forces of nature. The result has been that everywhere civilised populations have multiplied at a great rate, in a way that has never before occurred. But now this period seems to have definitely come to an end, and to have been succeeded by a new period characterised by three features which threaten to exert a most deleterious effect upon the innate mental qualities of peoples.

(1) The world is becoming filled up; the untouched wealth of enormous territories no longer lies open to the grasp of the bold and enterprising. The coloured races are entering into the economic competition in the way foreshadowed by the late C. H. Pearson[132]. The high organisation of every form of economic activity renders the competition for wealth everywhere extremely severe. And at the same time men have come to regard as necessities of life what, but a few generations ago, were the luxuries of the wealthy or unknown even to them; that is to say, the standard of comfort has risen greatly. The combined result of these changes is the increased difficulty of maintaining a family in the upper strata of society.

(2) There has been a great development of humanitarian sentiment, one result of which has been the breaking down of class-barriers and the perfecting of the social ladder; at the same time it has produced such changes of our laws and institutions as tend in an ever increasing degree to lighten the economic burdens of the poor and to consummate by social organisation the abolition of natural selection; that is to say, these changes are putting a stop to the repression by natural laws of the multiplication of the less fit, those least well endowed mentally and physically. The recent great decline of infant mortality is one evidence of this.

(3) The influence of religion and custom has weakened, and men are more disposed to adopt the naturalistic point of view, to believe that this life is not a mere preparation for an infinitely longer life elsewhere, but that it is all they can certainly reckon upon and, therefore, is to be made the most of; while at the same time they are oppressed by the severity of the economic competition and by a sense of the lack of any ultimate purpose, end, or sanction of human effort.