Recollecting, then, what conduct is--namely, the adjustment of acts to ends--and observing how this adjustment becomes more and more complete as the organism becomes more developed, we have to note the order of the ends to which the acts are adjusted. The first end, the first stage of evolving conduct, is the further prolongation of life. The next is that adjustment of acts to ends which furthers an increased amount of life. Thus far the ends are complete individual life. Then come those adjustments which have for their final purpose the life of the species. Then there is a third kind of conduct, which results from the fact that the multitudinous creatures which fill the earth can not live wholly apart from one another, but are more or less in presence of one another, are interfered with by one another. No one species can so act as to secure the greatest amount of life to its individuals and the preservation of the species--can make a successful adjustment of its acts to these ends--without interfering with the corresponding adjustments by other creatures of their acts to their ends. That some may live, others must die. Finally, when we contemplate those adjustments of acts to ends which miss completeness, because they can not be made by one creature without other creatures being prevented from making them, we reach the thought of adjustments such that each creature may make them without preventing them from being made by other creatures. Let me now quote Mr. Spencer's concrete illustrations of these abstract statements: "Recognizing men as the beings whose conduct is most evolved, let us ask under what conditions their conduct, in all three aspects of its evolution, reaches its limit. Clearly while the lives led are entirely predatory, as those of savages, the adjustments of acts to ends fall short of this highest form of conduct in every way. Individual life, ill carried on from hour to hour, is prematurely cut short; the fostering of offspring often fails, and is incomplete when it does not fail; and in so far as the ends of self-maintenance and race-maintenance are met, they are met by destruction of other beings, of different kind, or of like kind. In social groups formed by compounding and recompounding primitive hordes, conduct remains imperfectly evolved in proportion as there continue antagonisms between the groups and antagonisms between members of the same group--two traits necessarily associated; since the nature which prompts international aggression prompts aggression of individuals on one another. Hence, the limit of evolution can be reached by conduct only in permanently peaceful societies. That perfect adjustment of acts to ends in maintaining individual life and rearing new individuals, which is effected by each without hindering others from effecting like perfect adjustments, is, in its very definition, shown to constitute a kind of conduct that can be approached only as war decreases and dies out.