Thus, those ethical systems which make virtue, right, obligation, the cardinal aims, are seen to be complementary to those ethical systems which make welfare, happiness, pleasure, the cardinal aims. Spencer follows up this argument with a chapter on the relativity of pleasures and pains, and then proceeds with an argument against excessive altruism as, in the end, selfish, since it is destructive to the power for work and to individual life, diminishes the vigor of offspring, and finally results in the survival of the less altruistic as the fittest; this chapter is under the heading "Egoism versus Altruism." It is followed by a chapter on Altruism versus Egoism, in which is shown that some individual self-sacrifice, at least to offspring, is found far down in the scale of being; that altruism is, therefore, "no less primordial than self-preservation,"[47] and hence no less imperative; that this altruism, at first unconscious, becomes, in higher stages of evolution, conscious; and that if often selfish in motive, it may be without any element of conscious self-regard, although it conduces greatly to egoistic satisfaction. Indeed, pure egoism defeats itself, since pleasure palls by over-indulgence, is dulled by maturity, and almost destroyed by old age. He that can find pleasure in ministering to that of others has, however, a source of pleasure which may serve in place of personal pleasure. In the associated state, a certain altruism is, and must necessarily be, an advantage to each member of the community. Whatever conduces to the well-being of each is conducive to the well-being of all.