Without venturing further into a rather speculative region, I need only indicate the bearing of such considerations upon problems nearer home. It is often complained that the tendency of modern civilisation is to preserve the weakly, and therefore to lower the vitality of the race. This seems to involve inadmissible assumptions. In the first place, the process by which the weaker are preserved consists in suppressing various conditions unfavourable to human life in general. Sanitary legislation, for example, aims at destroying the causes of many of the diseases from which our forefathers suffered. If we can suppress the smallpox, we of course save many weakly children, who would have died had they been attacked. But we also remove one of the causes which weakened the constitutions of many of the survivors. I do not know by what right we can say that such legislation, or again, the legislation which prevents the excessive labour of children, does more harm by preserving the weak than it does good by preventing the weakening of the strong. One thing is at any rate clear: to preserve life is to increase the population, and therefore to increase the competition; or, in other words, to intensify the struggle for existence. The process is as broad as it is long. If we could be sure that every child born should grow up to maturity, the result would be to double the severity of the competition for support, What we should have to show, therefore, in order to justify the inference of a deterioration due to this process, would be, not that it simply increased the number of the candidates for living, but that it gave to the feebler candidates a differential advantage; that they are now more fitted than they were before for ousting their superior neighbours from the chances of support. But I can see no reason for supposing such a consequence to be probable or even possible. The struggle for existence, as I have suggested, rests upon the unalterable facts that the world is limited and population elastic. Under all conceivable circumstances we shall still have in some way or other to proportion our numbers to our supplies; and under all circumstances those who are fittest by reason of intellectual or moral or physical qualities will have the best chance of occupying good places, and leaving descendants to supply the next generation. It is surely not less true that in the civilised as much as in the most barbarous race, the healthiest are the most likely to live, and the most likely to be ancestors. If so, the struggle will still be carried on upon the same principles, though certainly in a different shape.