The incursions of barbaric pastoralists seem to do civilizations less harm in the long run than one might expect. Indeed, two dark ages and renaissances in Europe suggest a recurring pattern in which a renaissance follows an incursion by about 800 years. It may even be suggested that certain genes or traditions of pastoralists revitalize the conquered people with an ingredient of progress which tends to die out in a large panmictic population for the reasons already discussed. I have in mind altruism itself, or the part of the altruism which is perhaps better described as self-sacrificial daring. By the time of the renaissance it may be that the mixing of genes and cultures (or of cultures alone if these are the only vehicles, which I doubt) has continued long enough to bring the old mercantile thoughtfulness and the infused daring into conjunction in a few individuals who then find courage for all kinds of inventive innovation against the resistance of established thought and practice. Often, however, the cost in fitness of such altruism and sublimated pugnacity to the individuals concerned is by no means metaphorical, and the benefits to fitness, such as they are, go to a mass of individuals whose genetic correlation with the innovator must be slight indeed. Thus
probably slowly reduces its altruism of all kinds, including the kinds needed for cultural creativity (see also Eshel 1972).
But lest I be accused of merely appealing to W. D. Hamilton’s authority, let me argue as follows:
Civilization is nihilistic because it regresses creation from man the sexually moral animal to mere “eat or be eaten” evolution. Agreed, we cannot say all purpose is annihilated by this since, clearly, eat-or-be-eaten was a stage of creation founding later stages of creation. However, the annihilation of the very capacity for morality plus the annihilation of sexuality should suffice for the “purposes” of even the most committed nihilist.