Eighteenth century Scottish economist Adam Smith put forth the foundation for libertarian free-market economics by saying that if all individuals were allowed to act on their own individual best interest, the collective result would be good for the whole society. He posited an Invisible Hand that guided that process.
A couple of centuries later, Garrett Hardin, generally regarded as the father of ecology, offered the diametrically opposed view in a Science article, "The Tragedy of the Commons." The English Commons had traditionally been a public space where farmers could graze their cattle at no cost and no restrictions. As Hardin observed, it was in the individual self-interest of each farmer to enlarge his or her herd as much as possible, increasing revenue from the sale of milk and beef. And that's what happened; all the herds grew larger and larger.
Unfortunately, the amount of grass on the Commons did not increase; in fact, more cows meant less grass for each cow. The Commons became overgrazed. So what was in the individual self-interest of each farmer? If each cow was producing less milk because of its reduced intake of grass, the solution for an individual farmer was to further increase the herd. Even though each cow was producing less milk, the cumulative production of the herd might be sustained.
And that's what happened. Each herd was even further enlarged until the Commons finally collapsed, unable to feed the ever-growing population of cattle. "The Tragedy of the Commons" clearly illustrated that, contrary to Smith's view, each individual operating on behalf of his or her individual self-interest does not necessarily produce a positive collective result. In fact, it may produce disaster.
A similar process has occurred on a larger scale in terms of human population on the planet. In earlier agrarian times, with very high child mortality, it made sense for each couple of produce a large number of children. A large number of births in a family would better ensure that some children would live to adulthood. Those children provided a necessary work force for farming. And, as they grew older, a couple would depend on those children for support in their old age. Thus, a large family seemed intelligent from the standpoint of an individual couple.
As child mortality dramatically decreased and fewer families were farm-bound, the perceived value of large families persisted. Average family size has declined slowly and has never reached the point of simple replacement worldwide. As a consequence, total world population has grown dramatically.
Some demographers have calculated that our planet can sustain 1.5 billion to 2.0 billion humans at a comfortable (Western European) lifestyle. Today, there are 7.6 billion of us, projected to reach 9 or 10 billion by mid-century. We are steadily exhausting finite resources, such as fossil fuels, and land once used for growing food has been converted for housing, roads, and parking lots.
I think the clearest metaphor for humans on earth is a virus. An individual virus is a tiny biological agent, living in and consuming a much larger host. These tiny agents reproduce rapidly until they have exhausted and killed their host. In medicine, of course, we have developed inoculations and cures for many of the common viruses that attack us.
However, human beings bear a remarkable similarity to viruses, rapidly increasing in numbers and consuming our host: our Mother Earth. This metaphor is not perfect, of course. We humans will not "kill" the planet, though we are already killing many of the species that previously shared the planet with us. And as Garrett Hardin famously said, in an ecosystem, you cannot do only one thing. Thus, we may introduce insecticides that have the unintended effect of eliminating bees, who will no longer pollinate plants, which will cease to produce food for our consumption. Whoops!
The mistaken belief that individual self-interest will produce a collective good is producing a colossal, collective collapse. And that collapse will drag everyone down: those who thoughtlessly and selfishly focused only on their short-term self-interest and those who lived responsibly, doing what they could to preserve the ability of humans to live sustainably on the planet.
The only solution is for everyone--voluntarily or by law--to guide their behavior by what is best for the planet and all who live here.
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Dr. Earl Babbie of Hot Springs Village is the Campbell professor emeritus in behavioral sciences at Chapman University in Orange, Calif.
Editorial on 01/05/2019