Plagues and Peoples Read Online Free Page A

remains of key importance.

A F EW K EY C ONCEPTS
     
    Before proceeding with the story, a few remarks about parasitism, disease, pestilential infection, and related concepts may help to avoid confusion.
    Disease and parasitism play a pervasive role in all life. A successful search for food on the part of one organism becomesfor its host a nasty infection or disease. All animals depend on other living things for food, and human beings are no exception. Problems of finding food and the changing ways human communities have done so are familiar enough in economic histories. The problems of avoiding becoming food for some other organism are less familiar, largely because from very early times human beings ceased to have much to fear from large-bodied animal predators like lions or wolves. Nevertheless, one can properly think of most human lives as caught in a precarious equilibrium between the microparasitism of disease organisms and the macroparasitism of large-bodied predators, chief among which have been other human beings.
    Microparasites are tiny organisms—viruses, bacteria, or multi-celled creatures as the case may be—that find a source of food in human tissues suitable for sustaining their own vital processes. Some microparasites provoke acute disease and either kill their host after only a brief period of time, or provoke immunity reactions inside his body that kill them off instead. Sometimes, too, one of these disease-causing organisms is somehow contained within a particular host’s body so that he becomes a carrier, capable of infecting someone else without being noticeably sick himself. There are, however, other microparasites that regularly achieve more stable relations with their human hosts. Such infections no doubt take something away from their host’s bodily energies, but their presence does not prevent normal functioning.
    Macroparasites exhibit similar diversity. Some kill at once, as lions and wolves must do when feeding on human or any other kind of flesh; others allow the host to survive indefinitely.
    In very early times, the skill and formidability of human hunters outclassed rival predators. Humanity thus emerged at the very top of the food chain, with little risk of being eaten by predatory animals any more. Yet for a long time thereafter cannibalism almost certainly remained a significant aspect of the interaction of adjacent human communities. This put thesuccessful human hunters exactly on a level with a pride of lions or a pack of wolves.
    Later, when food production became a way of life for some human communities, a modulated macroparasitism became possible. A conqueror could seize food from those who produced it, and by consuming it himself become a parasite of a new sort on those who did the work. In specially fertile landscapes it even proved possible to establish a comparatively stable pattern of this sort of macroparasitism among human beings. Early civilizations, in fact, were built upon the possibility of taking only a part of the harvest from subjected communities, leaving enough behind to allow the plundered community to survive indefinitely, year after year. In the early stages the macroparasitic basis of civilization remained harsh and clear; only later and by slow degrees did reciprocal services between town and countryside develop importance enough to diminish the one-sidedness of tax and rent collection. To begin with, though, the hard-pressed peasantries that supported priests and kings and their urban hangers-on received little or nothing in return for the food they gave up, except for a somewhat uncertain protection from other, more ruthless and shortsighted plunderers.
    The reciprocity between food and parasite that has under-girded civilized history is matched by parallel reciprocities within each human body. The white corpuscles, which constitute a principal element in defenses against infection, actually digest intruders. Organisms they are unable to digest become