Malthus was born to a prosperous family. His father was a personal friend of the philosopher and skeptic David Hume and an acquaintance of Jean-Jacques Rousseau. The young Malthus was educated at home until his admission to Jesus College, Cambridge in 1784. There he studied many subjects and took prizes in English declamation, Latin and Greek. His principle subject was mathematics. He earned a masters degree in 1791 and was elected a fellow of Jesus College two years later. In 1797, he was ordained and became a country parson.
Malthus's views were largely developed in reaction to the optimistic views of his father and his associates, notably Rousseau and William Godwin. In An Essay on the Principle of Population, published in 1798, Thomas Malthus predicted population would outrun food supply, leading to a decrease in food per person. This prediction was based on the idea that population if unchecked increases at a geometric rate whereas the food supply grows at an arithmetic rate. (See Malthusian catastrophe for more information.) Only misery, moral restraint and vice (which for Malthus included contraception) could check excessive population growth. Malthus favoured "moral restraint" (including late marriage and sexual abstinence) as a check on population growth.
The influence of Malthus's theory of population was very great. Previously high fertility had been considered an economic plus since it increased the number of workers available to the economy. Malthus however looked at fertility from a new perspective and convinced most economist that even though high fertility might increase the gross output it tended to reduce output per capita. Many 20th century economists, such as Julian Simon, have criticised such conclusions.
However, Malthus' theory was also a key influence on both of the co-founders of modern evolutionary theory Charles Darwin and Alfred Russel Wallace. Darwin, in his book The Origin of Species, called his theory an application of the doctrines of Malthus in an area without the complicating factor of human intelligence. Wallace considered it "the most interesting coincidence" that both he and Darwin were independently led to the theory of evolution through reading Malthus. Ironically, given Malthus' own opposition to contraception, Malthus' work was also a strong influence on Francis Place (1771-1854), whose Neo-Malthusian movement was the first to advocate contraception.
Malthus married in 1804; He and his wife had 3 children. In 1805 he became Britain's (and possibly the world's) first professor in political economy at the East India Company College at Haileybury, Hertfordshire. Here he developed a theory of demand supply mismatches which he called gluts. Considered ridiculous at the time, his theory was later confirmed by the Great Depression and works of John Maynard Keynes. Malthus was buried at Bath Abbey, in England.