I should therefore be ready to admit, as a plausible conjecture, that the capacity for altruistic emotions and beliefs is a direct product of organic evolution; an attribute preserved and encouraged, because it is useful to the race, and transmitted from parents to offspring by physiological inheritance. On this theory loyalty in some shape or other is as natural to man as maternal affection is natural to mammals. Doubtless it is more variable in strength, more flexible in direction, more easily smothered by competing egoisms; but the capacity for it is not less innate, and not less necessary in the struggle for existence. But when we ask how far selection has been responsible for the development of high altruistic ideals out of primitive forms of loyalty, we touch on problems of much greater complexity. Evidently there has been a profound moral transformation in the course of ages. None suppose that ethical values are appraised in the twentieth century as they were in the first stone age. But what has caused the change is not so clear. There are obvious, and, I think, insurmountable difficulties in attributing it to organic selection. Selection is of the fittest—of the fittest to survive. But in what consists this particular kind of fitness? The answer from the biological point of view is quite simple: almost a matter of definition. That race is “fit” which maintains its numbers; and that race is fittest which most increases them. The judge of such “fitness” is not the moralist or the statesman. It is the Registrar-General. So little is “fitness” inseparably attached to excellence, that it would be rash to say that there is any quality, however unattractive, which might not in conceivable circumstances assist survival. High authorities, I believe, hold that at this moment in Britain we have so managed matters that congenital idiots increase faster than any other class of the population. If so, they must be deemed the “fittest” of our countrymen. No doubt this fact, if it be a fact, is an accident of our social system. Legislation has produced this happy adaptation of environment to organism, and legislation might destroy it. The fittest to-day might become the unfittest to-morrow. But this is nothing to the purpose. That part of man’s environment which is due to man does no doubt usually vary more quickly than the part which is due to nature; none the less is it environment in the strictest sense of the word. The theory of selection draws no essential distinction between (say) the secular congelation of a continent in the ice age, and the workings of the English Poor Law in the twentieth century. It is enough that each, while it lasts, favours or discourages particular heritable variations, and modifies the qualities that make for “survival.”