§ 5. Turn we now to a further aspect of the phenomena, separate from, but necessarily associated with, the last. Thus far we have considered only those adjustments of acts to ends which have for their final purpose complete individual life. Now we have to consider those adjustments which have to their final purpose the life of the species.
Self-preservation in each generation has all along depended on the preservation of offspring by preceding generations. And in proportion as evolution of the conduct subserving individual life is high, implying high organization, there must previously have been a highly-evolved conduct subserving nurture of the young. Throughout the ascending grades of the animal kingdom, this second kind of conduct presents stages of advance like those which we have observed in the first. Low down, where structures and functions are little developed, and the power of adjusting acts to ends but slight, there is no conduct, properly so named, furthering salvation of the species. Race-maintaining conduct, like self-maintaining conduct, arises gradually out of that which cannot be called conduct: adjusted actions are preceded by unadjusted ones.
Protozoa spontaneously divide and sub-divide, in consequence of physical changes over which they have no control; or, at other times, after a period of quiescence, break up into minute portions which severally grow into new individuals. In neither case can conduct be alleged. Higher up, the process is that of ripening, at intervals, germ-cells and sperm-cells, which, on occasion, are sent forth into the surrounding water and left to their fate: perhaps one in ten thousand surviving to maturity. Here, again, we see only development and dispersion going on apart from parental care. Types above these, as fish which choose fit places in which to deposit their ova, or as the higher crustaceans which carry masses of ova about until they are hatched, exhibit adjustments of acts to ends which we may properly call conduct, though it is of the simplest kind. Where, as among certain fish, the male keeps guard over the eggs, driving away intruders, there is an additional adjustment of acts to ends; and the applicability of the name conduct is more decided.
Passing at once to creatures far superior, such as birds, which, building nests and sitting on their eggs, feed their broods for considerable periods, and give them aid after they can fly; or such as mammals which, suckling their young for a time, continue afterward to bring them food or protect them while they feed, until they reach ages at which they can provide for themselves; we are shown how this conduct which furthers race-maintenance evolves hand-in-hand with the conduct which furthers self-maintenance. That better organization which makes possible the last, makes possible the first also.
Mankind exhibit a great progress of like nature. Compared with brutes, the savage, higher in his self-maintaining conduct, is higher too in his race-maintaining conduct. A larger number of the wants of offspring are provided for; and parental care, enduring longer, extends to the disciplining of offspring in arts and habits which fit them for their conditions of existence. Conduct of this order, equally with conduct of the first order, we see becoming evolved in a still greater degree as we ascend from savage to civilized. The adjustments of acts to ends in the rearing of children become far more elaborate, alike in number of ends met, variety of means used, and efficiency of their adaptations; and the aid and oversight are continued throughout a much greater part of early life.
In tracing up the evolution of conduct, so that we may frame a true conception of conduct in general, we have thus to recognize these two kinds as mutually dependent. Speaking generally, neither can evolve without evolution of the other; and the highest evolutions of the two must be reached simultaneously.
§ 6. 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.
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 larvæ. 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 favorable 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 toward the close of life. Death by starvation from inability to catch prey, shows a falling short of conduct from its ideal.
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.
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