To conclude, however, that on reaching a perfect adjustment of acts to ends subserving individual life and the rearing of offspring, the evolution of conduct becomes complete, is to conclude erroneously. Or rather, I should say, it is an error to suppose that either of these kinds of conduct can assume its highest form, without its highest form being assumed by a third kind of conduct yet to be named. (§6 ¶1)

The multitudinous creatures of all kinds which fill the Earth, cannot live wholly apart from one another, but are more or less in presence of one another—are interfered with by one another. In large measure the adjustments of acts to ends which we have been considering, are components of that struggle for existence carried on both between members of the same species and between members of different species; and, very generally, a successful adjustment made by one creature involves an unsuccessful adjustment made by another creature, either of the same kind or of a different kind. That the carnivore may live herbivores must die; and that its young may be reared the young of weaker creatures must be orphaned. Maintenance of the hawk and its brood involves the deaths of many small birds; and that small birds may multiply, their progeny must be fed with innumerable sacrificed worms and larvae. Competition among members of the same species has allied, though less conspicuous, results. The stronger often carries off by force the prey which the weaker has caught. Monopolizing certain hunting grounds, the more ferocious drive others of their kind into less favourable places. With plant-eating animals, too, the like holds: the better food is secured by the more vigorous individuals, while the less vigorous and worse fed, succumb either directly from innutrition or indirectly from resulting inability to escape enemies. That is to say, among creatures whose lives are carried on antagonistically, each of the two kinds of conduct delineated above, must remain imperfectly evolved. Even in such few kinds of them as have little to fear from enemies or competitors, as lions or tigers, there is still inevitable failure in the adjustments of acts to ends towards the close of life. Death by starvation from inability to catch prey, shows a falling short of conduct from its ideal. (§6 ¶2)

This imperfectly-evolved conduct introduces us by antithesis to conduct that is perfectly evolved. Contemplating these adjustments of acts to ends which miss completeness because they cannot be made by one creature without other creatures being prevented from making them, raises the thought of adjustments such that each creature may make them without preventing them from being made by other creatures. That the highest form of conduct must be so distinguished, is an inevitable implication; for while the form of conduct is such that adjustments of acts to ends by some necessitate non-adjustments by others, there remains room for modifications which bring conduct into a form avoiding this, and so making the totality of life greater. (§6 ¶3)

From the abstract let us pass to the concrete. 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 re-compounding 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 llfe 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. (§6 ¶4)

A gap in this outline must now be filled up. There remains a further advance not yet even hinted. For beyond so behaving that each achieves his ends without preventing others from achieving their ends, the members of a society may give mutual help in the achievement of ends. And if, either indirectly by industrial co-operation, or directly by volunteered aid, fellow citizens can make easier for one another the adjustments of acts to ends, then their conduct assumes a still higher phase of evolution; since whatever facilitates the making of adjustments by each, increases the totality of the adjustments made, and serves to render the lives of all more complete. (§6 ¶5)