ABSTRACT
In 1798, British cleric Thomas Robert Malthus (Figure 11.1) published his inuential An Essay on the Principle of Population. In it, he was perhaps the rst to propose that the human population has limits and cannot grow unabated. This idea appears to square with the awareness of the ancients. The Book of Revelation, for example, proposes that war, famine, and disease limit population.1 Malthus uses these unpleasantries as checks on human population growth. Malthus understood that “the means of subsistence” (the food supply) determines the limit above which population cannot grow.2 The level of subsistence checks every facet of human growth, be it the economy, society, or politics. The Enlightenment faith in progress through scientic rationalism did not impress Malthus, who ventured two postulates. First, food is essential to human survival. Second, the libido is powerful, causing humans to reproduce at a rate that is unlikely to abate in the future. Human sexuality is akin to an impulse that few resist. In this context, the “power of population is indenitely greater than the power in the earth to produce subsistence for man.”3 Population, Malthus held, increases geometrically unless catastrophe befalls it, whereas food supply increases only arithmetically. That is, population cannot outstrip the food supply without causing high mortality to match the birth rate, creating a dismal equilibrium. Humankind, and here Malthus counters the optimism of the Enlightenment, cannot reason its way out of these laws of nature. Under these conditions, humans cannot perfect themselves or society, in general. Famine is perhaps the most obvious limiting factor correlated to food supply, for when food is scarce people starve. The food supply is not as elastic as the human capacity for reproduction so that population tends to outrun its food supply, causing a check on population. The checks to population fall heavily on the poor, who cannot afford sufcient food for their children so that infant mortality is high. As population increases, food becomes too expensive for the poor. Again high mortality ensues. Agricultural improvement is possible but cannot continue unabated. Moreover, the conversion of land from crops to pasture exacerbates the population crisis.
