struggle for survival may fail to bring into existence organisms that would be highly beneficial: and in the economic world the demand for any industrial arrangement is not certain to call forth a supply, unless it is something more than a mere desire for the arrangement, or a need for it. It must be an efficient demand; that is, it must take effect by offering adequate payment or some other benefit to those who supply it. (2) A mere desire on the part of employees for a share in the management and the profits of the factory in which they work, or the need on the part of clever youths for a good technical education, is not a demand in the sense in which the term is used when it is said that supply naturally and surely follows demand. This seems a hard truth: but some of its harshest features are softened down by the fact that those races, whose members render services to one another without exacting direct recompense are not only the most likely to flourish for the time, but most likely to rear a large number of descendants who inherit their beneficial habits.
2. Even in the vegetable world a species of plants, however vigorous in its growth, which should be neglectful of the interests of its seeds, would soon perish from the earth. The standard of family and race duty is often high in the animal kingdom; and even those predatory animals which we are accustomed to regard as the types of cruelty, which fiercely utilize the environment and do nothing for it in return, must yet be willing as individuals to exert themselves for the benefit of their offspring. And going beyond the narrower interests of the family to those of the race, we find that among so-called social animals, such as bees and ants, those races survive in which the individual is most energetic in performing varied services for the society without the prompting of direct gain to himself.
But when we come to human beings, endowed with reason and speech, the influence of a tribal sense of duty in strengthening the tribe takes a more varied form. It is true that in the ruder stages of human life many of the services rendered by the individual to others are nearly as much due to hereditary habit and unreasoning impulse, as are those of the bees and ants. But deliberate, and therefore moral, self-sacrifice soon makes its appearance; it is fostered by the far-seeing guidance of prophets and priests and legislators, and is inculcated by parable and legend. Gradually the unreasoning sympathy, of which there are germs in the lower animals, extends its area and gets to be deliberately adopted as a basis of action: tribal affection, starting from a level hardly higher than that which prevails in a pack of wolves or a horde of banditti, gradually grows into a notable patriotism; and religious ideals are raised and purified. The races in which these qualities are the most highly developed are sure, other things being equal, to be stronger than others in war and in contests with famine and disease; and ultimately to prevail. Thus the struggle for existence causes in the long run those races of men to survive in which the individual is most willing to sacrifice himself for the benefit of those around him; and which are consequently the best adapted collectively to make use of their environment.
Unfortunately however not all the qualities which enable one race to prevail over another benefit mankind as a whole. It would no doubt be wrong to lay very much stress on the fact that warlike habits have often enabled half-savage races to reduce to submission others who were their superiors in every peaceful virtue; for such conquests have gradually increased the physical vigour of the world, and its capacity for great things, and ultimately perhaps have done more good than harm. But there is no such qualification to the statement that a race does not establish its claim to deserve well of the world by the mere fact that it flourishes in the midst or on the surface of another race. For, though biology and social science alike show that parasites sometimes benefit in unexpected way