An Essay on the Principle of Population

First published without an author’s name in 1798, the work was soon attributed to Thomas Robert Malthus. It argued that human population, if unchecked, grows in a geometric ratio (doubling roughly every twenty-five years), while the food supply can only increase in an arithmetic ratio. This disparity, Malthus warned, would inevitably lead to shortages and famine unless birth rates were deliberately reduced. Although not the first book on population, it sparked intense debate in Britain and helped bring about the Census Act of 1800, which established a national census in England, Wales, and Scotland beginning in 1801 and continuing every decade.

Malthus published a heavily revised second edition in 1803, and the final, sixth edition appeared in 1826. In 1830 he issued a condensed version, A Summary View on the Principle of Population, responding to critics. The sixth edition was later cited as a key influence by both Charles Darwin and Alfred Russel Wallace in developing the theory of natural selection.

A central portion of the book set out what became known as the Malthusian Law of Population, which holds that rising population increases the labor supply and drives down wages, perpetuating poverty. Malthus saw two types of checks on population: preventive checks (such as delayed marriage or celibacy) and positive checks (such as hunger, disease, and war). He opposed government poor relief, arguing it ultimately harmed the poor by raising prices and undermining self-reliance, though he supported private benevolence. As a clergyman, he addressed the problem of suffering, suggesting that the threat of poverty spurred human industry and virtue, and that humanity itself was responsible for its own misery.