An Essay on the Principle of Population by Thomas Malthus was first published anonymously in 1798. Its core argument, that human population will inevitably outgrow its capacity to produce food, widely influenced the field of early 19th century economics and social science. Immediately after its first printing, Malthus’s essay garnered significant attention from his contemporaries, and he soon felt the need to reveal his identity. Although it was highly controversial, An Essay on the Principle of Population nevertheless left its impression on foundational 19th century theorists, such as naturalist Charles Darwin and economists Friedrich Engels and Karl Marx. Modern economists have largely dismissed the Malthusian perspective. Principally, they argue Malthus underappreciated the exponential growth brought about by the advent of the Industrial Revolution; by the discovery of new energy sources, such as coal and electricity; and later by further technological innovations. These modern criticisms are easily defended with historical retrospective.

Malthus’s essay has been revised several times since its publication. This summary focuses on the contents of the first edition. In 1806, Malthus revamped his work into four books to further discuss points of contention in the first edition and address many of the criticisms it received. Three more editions followed (published in 1807, 1817, and 1826 respectively), each modifying or clarifying points made in the second version.

Although Malthus’s basic stance on the unsustainable growth of population to food production remains the same throughout all versions, the most dramatic change in format and content is found between the first and second editions. The first edition is notable for its long and detailed critique of the works of William Godwin, Marquis de Condorcet, and Richard Price on the perfectibility of humankind. Its lack of “hard data” and its unpracticed opinions on sex and reproduction were heavily criticized by his contemporaries. The 1806 publication, written at a later point in Malthus’s life, attempts to address these issues by focusing less on critiquing the works of other theorists and offering better data on the fluctuation of population growth throughout various European countries and colonies (Malthus, Thomas Robert. An Essay on the Principle of Population: the 1803 edition. Yale University Press. 2018).

Summary

An Essay on the Principle of Population begins with a preface and is subsequently separated into eleven chapters. The preface reveals that a conversation with a friend on the future improvement of society was what sparked Malthus’s inspiration for this work. Chapter 1 further credits the works of David Hume, Alfred Russel, Adam Smith, and many others for inspiring his own writing. He postulates that population grows exponentially, whereas food production only increases in a linear fashion. This disparity in power will inevitably lead to overpopulation and an inadequate amount of food for subsistence.

Chapter 2 further details the above premise. Malthus imagines a world of abundance. In such a society of ease and leisure, no one would be anxious about providing for their families, which incentivizes them to marry early, causing birth rates to explode. When there are too many people and too little an increase in food to support them, the lower classes will be plunged into a state of misery. Thus, Malthus concludes that population growth only happens when there is an increase in subsistence, and misery and vice keep the world from overpopulation.

In chapters 3, 4, and 5, Malthus applies his theory to different stages of society. He argues that “savage” and shepherding societies never grow as fast as their “civilized” counterparts because various miseries keep their numbers in check. Among “savage” societies, a lack of food and a general disrespect of personal liberties prevent their numbers from increasing rapidly. Shepherding communities, meanwhile, often wage war over territories and suffer a high mortality rate. Civilized societies grew rapidly after adopting the practice of tilling, but due to exhausting most fertile land, their numbers no longer increase at the same rate as before.

The following two chapters are notable because they are the only ones that contain hard data. Malthus cites philosopher Richard Price for his analysis of population in America and references demographer Johann Peter Süssmilch for his work on Prussia. Malthus uses both these examples to prove that population fluctuates in accordance with the quantity of food produced. Chapters 8 and 9 are dedicated to critiquing mathematician Marquis de Condorcet’s work while chapters 10 to 15 do the same for political philosopher William Godwin. Malthus rejects the idea of mankind as infinitely perfectible and dismisses charity as a method to relieve poverty.

Chapters 16 and 17 propose the increase of food production as the only solution to reduce extreme poverty and misery among the lower class. Malthus maintains that donating funds is but a temporary relief to aid the most unfortunate; only a permanent increase in agricultural yield can grow the lower class’s purchasing power. Nevertheless, the final two chapters remind readers that misery and happiness must coexist. The law of nature, the way of living intended by God and demonstrated by Malthus’s population theory, requires both wealth and poverty to function.