I refer to those hindrances to the survival of the fittest which in earlier times resulted from the undiscriminating charities of monasteries and in later times from the operation of Poor Laws. Of course if the competition which increasing pressure of population entails, is prevented from acting on a considerable part of the community, such part, saved from the needed intellectual and moral stress, will not undergo any further mental development; and must ever tend to leave a posterity, and an increasing posterity, in which none of that higher individuation which checks genesis takes place. Such State-meddlings with the natural play of actions and reactions produce a further evil equally great or greater. For those who are not self-maintained, or but partially self-maintained, are supplied with the means they lack by the better members of the community; and these better members have thus not only to support themselves and their offspring, but also to support or aid the inferior members and their offspring. The under-working of one part is accompanied by the over-working of the other part—by a working which at each stage of progress exceeds that which the normal conditions necessitate, and results sometimes in illness, premature age, or death, or in lessened number of children, or in imperfect rearing of children: the bad are fostered and the good are repressed.
It does not follow that the struggle for life and the survival of the fittest must be left to work out their effects without mitigation. It is contended only that there shall not be a forcible burdening of the superior for the support of the inferior. Such aid to the inferior as the superior voluntarily yield, kept as it will be within moderate limits, may be given with benefit to both—relief to the one, moral culture to the other. And aid willingly given (little to the least worthy and more to the most worthy) will usually be so given as not to further the increase of the unworthy. For in proportion as the emotional nature becomes more evolved, and there grows up a higher sense of parental responsibility, the begetting of children that cannot be properly reared will be universally held intolerable. If, as we see, public opinion in many places and times becomes coercive enough to force men to fight duels, we can scarcely doubt that at a higher stage of evolution it may become so coercive as to prevent men from marrying improvidently. If the frowns of their fellows can make men commit immoral acts, surely they may make men refrain from immoral acts—especially when the actors themselves feel that the threatened frowns would be justified. Hence with a higher moral nature will come a restriction on the multiplication of the inferior.
In brief, the sole requirement is that there shall be no extensive suspension of that natural relation between merit and benefit which constitutes justice. Holding, then, that this all-essential condition will itself come to be recognized and enforced by a more evolved humanity, let us consider what is the goal towards which the restraint on genesis by individuation progresses.
§ 375a. Supposing the Sun’s light and heat, on which all terrestrial life depends, to continue abundant for a period long enough to allow the entire evolution we are contemplating; there are still certain changes which must prevent such complete adjustment of human nature to surrounding conditions, as would permit the rate of multiplication to become equal to the rate of mortality. As before pointed out ([§ 148]), during an epoch of 21,000 years each hemisphere goes through a cycle of temperate seasons and seasons extreme in their heat and cold—variations which are themselves alternately exaggerated and mitigated in the course of far longer cycles; and we saw that these cause perpetual ebbings and flowings of species over different parts of the Earth’s surface. Further, by slow but inevitable geologic changes, especially those of elevation and subsidence, the climate and physical characters of every habitat are modified; while old habitats are destroyed and new are formed. This, too, we noted as a constant cause of migrations and of resulting alterations of environment. Now though the human race differs from other races in having a power of artificially counteracting external changes, yet there are limits to this power; and, even were there no limits, the changes could not fail to work their effects indirectly, if not directly. If, as is thought probable, these astronomic cycles entail recurrent glacial periods in each hemisphere, then parts of the Earth which are at one time thickly peopled, will at another time be almost deserted, and vice versâ. The geologically-caused alterations of climate and surface, must produce further slow re-distributions of population; and other currents of people, to and from different regions, will be necessitated by the rise of successive centres of higher civilization. Consequently, mankind cannot but continue to undergo changes of environment, physical and moral, analogous to those which they have thus far been undergoing. Such changes may eventually become slower and less marked; but they can never cease. And if they can never cease there can never arise a perfect adaptation of human nature to its conditions of existence. To establish that complete correspondence between inner and outer actions which constitutes the highest life and greatest power of self-preservation, there must be a prolonged converse between the organism and circumstances which remain the same. If the external relations are being altered while the internal relations are being adjusted to them, the adjustment can never become exact. And in the absence of exact adjustment, there cannot exist that theoretically-highest power of self-preservation with which there would co-exist the theoretically-lowest power of race-production.
Hence though the number of premature deaths may ultimately become very small, it can never become so small as to allow the average number of offspring from each pair to fall so low as two. Some average number between two and three may be inferred as the limit—a number, however, which is not likely to be quite constant, but may be expected at one time to increase somewhat and afterwards to decrease somewhat, according as variations in physical and social conditions lower or raise the cost of self-preservation.
To this qualification must be added a further qualification. The foregoing argument tacitly assumes that the causes described will continuously operate on all mankind; whereas a survey of the facts makes it clear that some parts only of the Earth’s surface are capable of bearing high types of civilization, and consequently high types of Man. There must remain hereafter, as there are now, considerable parts of its surface which can support only groups of nomads, or other groups obliged by their habitats to lead simple and inferior kinds of life. Only by subjection to the discipline we have been contemplating can there be produced the fully-developed Man; and evidently in many parts of the world this discipline will continue to be eluded. Not only must we conclude that the varieties of our race now living in desert regions and arctic climates will continue hereafter to do so, but we may conclude that always, as now, a certain proportion of men who are born in civilized societies, impatient of the stress which pressure of population puts on them, will escape into unoccupied or sparsely-peopled regions, where they can lead unrestrained lives though lives of hardship. Recognizing as we must the probability that in common with all other things, humanity will continue to differentiate and produce a more heterogeneous assemblage of types, we must infer that only in some of the highest of these will the antagonism of individuation and genesis have the anticipated effects.
Restricting ourselves to these, then, we may conclude that in the end, pressure of population and its accompanying evils will almost disappear; and will leave a state of things requiring from each individual little more than a normal and pleasurable activity. Cessation in the decrease of fertility implies cessation in the development of the nervous system; and this implies a nervous system which has become equal to all that is demanded of it—has not to do more than is natural to it. But that exercise of faculties which does not exceed what is natural, constitutes gratification.
The necessary antagonism of Individuation and Genesis, not only, then, fulfils the à priori law of maintenance of race, from the monad up to Man, but ensures final attainment of the highest form of this maintenance—a form in which the amount of life shall be the greatest possible and the births and deaths the fewest possible. From the beginning pressure of population has been the proximate cause of progress. It produced the original diffusion of the race. It compelled men to abandon predatory habits and take to agriculture. It led to the clearing of the Earth’s surface. It forced men into the social state; made social organization inevitable; and has developed the social sentiments. It has stimulated to progressive improvements in production, and to increased skill and intelligence. It is daily thrusting us into closer contact and more mutually-dependent relationships. And after having caused, as it ultimately must, the due peopling of the globe, and the raising of its habitable parts into the highest state of culture—after having perfected all processes for the satisfaction of human wants—after having, at the same time, developed the intellect into competence for its work, and the feelings into fitness for social life—after having done all this, the pressure of population must gradually approach to an end—an end, however, which for the reasons given it cannot absolutely reach.
§ 377. In closing the argument let us not overlook the self-sufficingness of those universal processes by which the results reached thus far have been wrought out, and which may be expected to work out these future results.
Evolution under all its aspects, general and special, is an advance towards equilibrium. We have seen that the theoretical limit towards which the integration and differentiation of every aggregate advances, is a state of balance between all the forces to which its parts are subject, and the forces which its parts oppose to them (First Prin. § 170). And we have seen that organic evolution is a progress towards a moving equilibrium completely adjusted to environing actions.