In the first place, it is desirable to characterise briefly Darwin’s own contribution to this matter.  The suggestion made by him deals almost entirely with what I have called the development of morality, not with the ethics of evolution; and perhaps it may seem to us now a rather obvious suggestion.  But he was the first to make this suggestion; and it comes from him as a direct application of the theory he had established with regard to animal development.  His suggestion is simply this—­that moral qualities are selected in the struggle for existence in much the same way as purely physical or animal excellences are selected, that is, by their contributing to the continued and more efficient life of the organism.  But Darwin saw very clearly that the qualities which are recognised as moral are not by any means in all cases contributory to individual success and efficiency.  They are not all of them qualities that contribute to the success of one individual in his struggle with other individuals for the means of subsistence.  We may say that courage, prudence, self-reliance, will have that effect, and that consequently in the struggle for life the individuals who show such qualities will have a better chance of survival than those without them.  But what about qualities such as sympathy, willingness to help another, obedience, and faithfulness to a community or to a cause?  Clearly, these are not qualities which are of special assistance to the individual.  But they are qualities which are or may be of very great importance to the tribe or community of individuals.  Supposing such qualities of mutual help, of willingness even to sacrifice oneself for others—­the qualities which are commonly grouped as expressions of the social instinct,—­supposing these to have been somehow developed in the members of a tribe, that tribe would, other things being equal, have an advantage in a struggle with another tribe whose members did not possess these qualities.  Now the advantage thus gained in the struggle would be a case of the operation of natural selection:  it would exterminate or weaken the tribe without these social qualities, and it would thus give opportunity for the growing efficiency of the tribe that possessed them.

Put in the briefest way, this is the explanation which Darwin gave of the growth of the social qualities in mankind; and the social qualities make up, to a large extent at any rate, what we call moral qualities.  Darwin, however, saw further than this:  he saw that, while this might account for the development of what we may call savage and barbarian virtues, there was in civilised mankind a development of sympathy which went far beyond this, and which one could not with good reason account for by asserting that it rendered assistance to the community in its struggle for existence with other communities.

Thus, with regard to the former question, he says:  “A tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to aid one another, and to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural selection[1].”