One of the most influential books on economics ever written, Thomas Robert Malthus’s An Essay on the Principle of Population remains one of the most controversial too. This 1798 work inspired naturalists Charles Darwin and Alfred Russel Wallace to develop the theory of natural selection. But it has also sparked criticism—Karl Marx famously called Malthus a “lackey of the bourgeoisie.” Yet this hasn’t stopped leading present-day environmentalists from taking up Malthus’s ideas.
Malthus foresees a time when available resources will not sustain the growing population. To save society, he concludes, population growth must be reined in. Malthus advocates minimizing government support for the poor, which he believes leads to more births and ultimately more hardship. He also insists that individual sexual restraint is a vital way to control population growth.
The adjective “Malthusian” still pops up today, describing a group of thinkers and writers who share a particular concern about overpopulation—and a common approach to its analysis.