Thomas Malthus wasn’t really a bad man. It’s just that he had a really terrible idea—that the world always contains too many human beings. Put a little more gently: Malthus thought that human beings couldn’t be trusted to keep their numbers in check and maintain a prudent presence in the order of creation. Malthus, whose very surname begins with the Latin mal-, meaning evil, bad, or disease, and seems to invoke malignancy, maliciousness, and malintent, is really not so bad. In fact, his name derives from malthouse, a building in which grains are prepared for use in brewing. It’s just that Malthus set us to viewing one another with suspicion, envy, and jealousy—a malevolent brew that shifts our attention from what we might contribute to what we stand to lose to one another.

Things didn’t begin so badly for Thomas Malthus. He was born in 1766 into privilege. His father was a friend of the great Scottish philosopher David Hume and an admirer of Rousseau, whose Emile inspired the younger Malthus’s upbringing. Admitted to Jesus College, Cambridge, Malthus quickly distinguished himself as a student, winning prizes in classics and mathematics. Thereafter, he took holy orders and became a parish curate. Later he married, fathering two daughters and a son, and he subsequently became a professor of history and political economy at the East India Company’s college. It was in 1798 that he published his greatest work, An Essay on the Principle of Population as It Affects the Future of Improvement of Society.

Malthus was responding to the writings of Godwin, Condorcet, and others, whose hopes for growing happiness for humanity he regarded as excessively optimistic. Having perceived through his work in the parish that he always seemed to be performing more baptisms than funerals, he began to conduct demographic investigations that convinced him that human populations inevitably tend to outstrip the resources available to them, or more concretely, that food supplies grow arithmetically while the number of people grows geometrically. As Malthus puts it, “The perpetual tendency of the race of man to increase beyond the means of subsistence is one of the general laws of animated nature, which we can have no reason to expect to change.”

Counteracting the tendency of human populations to explode are two forces, which Malthus labels “preventive” and “positive” checks. Preventive checks include delays in childbearing or the avoidance of childbearing altogether. Women who begin to have children later in life tend to have fewer children, and those who never marry, the conventions of the day allowed him to assume, would bear no children at all. Additional preventive checks include moral restraint—the hope that some will refrain from childbearing out of a concern for the welfare of the children they do bear, who are difficult enough for poor families to support—and legislation, which might prove politically impossible to enact. China’s recent one-child policy is an extreme version of the latter. Malthus held out little hope for such restraints:

The laboring poor, to use a vulgar expression, seem always to live from hand to mouth. Their present wants employ their whole attention, and they seldom think of the future. Even when they have an opportunity of saving, they seldom exercise it, but all that is beyond their present necessities goes, generally speaking, to the ale house.

The positive checks included war, plague, and famine. If people failed to constrain their rate of reproduction, nature would eliminate the problem of overpopulation when competition over scarce resources brought cities and nations into conflict with one another, overcrowding led to epidemics of disease, or there were simply too many mouths to feed. Malthus saw in these principles not merely a description of what in fact happens but a warrant to will it. He writes,

It is an evident truth that, whatever may be the rate of increase in the means of subsistence, the increase in population must be limited by it, at least after the food has been divided into the smallest shares that will support life. All the children born, beyond what would be required to keep up the population to this level, must necessarily perish, unless room be made for them by the deaths of grown persons. To act consistently, therefore, we should facilitate, instead of foolishly and vainly endeavoring to impede, the operation of nature in producing this mortality, and if we dread the too frequent visitation of the horrid form of famine, we should sedulously encourage the other forms of destruction, which we compel nature to use.

In contrast to the optimists of his day, Malthus may be regarded as a political pessimist. His account renders poverty the inescapable lot of mankind. At best, efforts to reduce poverty are almost certain to fail, and at worst, they will prove counterproductive. Charity, for example, merely exacerbates the problem. By putting more food in the mouths of the poor, charity workers act in unwitting collusion with the tendency for numbers to grow beyond the means of support. England’s poor laws, Malthus contended, encouraged large families and merely increased the numbers of the miserable and dying. It would have been better had they never existed, thereby increasing “the aggregate mass of happiness among the common people.” 

Malthus was, of course, wrong. For one thing, he never considered that the resources available to support populations might exceed expectations. Consider the work of the 20th-century American agronomist Norman Borlaug, whose “green revolution” dramatically increased crop yields and garnered him the Nobel Peace Prize. Some have even suggested that Borlaug saved more lives than any single human being who has ever lived. Malthus also failed, though understandably, to anticipate the introduction of contraceptives. More significantly, he failed to foresee the possibility that, enabled to control their own fertility, people might choose to limit their fecundity in order to increase their standard of living. In general, richer nations such as the US, Germany, and Japan have relatively low fertility rates. In fact, to increase standards of living, such nations need not fewer but more births.

Yet it was not only as a forecaster that Malthus was wrong. He was also wrong in a moral sense, and in large part because of the influence he exerted on other thinkers, such as Darwin. Malthus’s closed-fisted nature, in which resources are never sufficient, played a crucial role in shaping Darwin’s conception of a biological world dominated by a principle of competition. If the earth provides enough for every organism, then each can live and let live. But in a world characterized by scarcity, a struggle to survive inevitably ensues, in which organisms better adapted to prevailing conditions survive and those that do not perish. It was but a small step from Darwin’s “survival of the fittest,” repeatedly recharged by Malthusianism, to eugenics, the effort to rebalance the fit and unfit.

Malthus evinces an awareness of the possibility of something very much akin to eugenics but dismisses it as impractical. Considering the notion that some enlightened families might take steps to protect their best characteristics, he writes,

I know of no well-directed attempts of this kind, except in the ancient family of the Bickerstaffs, who are said to have been very successful in whitening the skins and increasing the height of their race by prudent marriages, particularly by that very judicious cross with Maud, the milk-maid, by which some capital defects in the constitutions of the family were corrected.

Inspired by Darwin, many intellectual descendants of Malthus entertained no such laments, and instead advocated heartily for both negative eugenics—programs to reduce the numbers of people bearing undesirable traits—and positive eugenics—programs aiming to increase the numbers of people with desirable traits.

Perhaps the most baleful feature of this benign man’s theory is the scarcity mentality it both posits and reinforces, and which has crept into contemporary thinking in biology, environmentalism, and economics. According to Malthus, nature is a despot—in Longfellow’s formulation, “red in tooth and claw.” Life is a zero-sum proposition, in which to get enough for oneself and one’s own, others must be denied existence. Should they manage to find their way into the world, they must endure want and misery before suffering an early death. Malthus’s is a desperate world—a crowded lifeboat, a tragedy of the commons, a prisoner’s dilemma. One person’s happiness entails another’s misery, and the prudent must jealously guard everything they have for fear the imprudent will gobble it up.