Malthus
2 of the 7 encyclopedias on this shelf carry an entry for Malthus. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
mal thus, Thomas Robert (1766-1834), a political economist of England. He was educated for the church, but led the life of a college professor. Malthus is known for his famous Essay on the Principles of Population, published in 1798. In this work he set forth what is known as the Malthusian Doctrine, to the effect that the population of the world has a tendency to increase much faster than the food supply, resulting in crowded centers of population and consequent misery. He took a very serious view of the situation and urged upon parents the propriety of raising small families, a doctrine directly opposite to that of President Roosevelt and others with greater confidence in the future of civilization. According to Malthus, population increases geometrically as 3, 9, 27, 81, 243, etc., while the means of support increase arithmetically as in the series 3, 6, 9, 12, 15, etc. This doctrine leaves out of account both the influence of scientific inventions upon the food supply and a probable tendency in dense populations to decrease the birth rate .
Collier's New Encyclopedia (1921)
THOMAS ROBERT, an English political economist; born in Al- 14, 1766. He bury, Surrey, England, Feb. Professor of was appointed about 1805, Economy in the col- History and Political Company at lege of the East India to hold that Haileybury, and continued His best known situation till his death. work, the "Essay on the Principle of Population," first appeared in 1798. It passed was subsequently enlarged, and through many editions. The Malthusian system is founded on the hypothesis that population increases in a geometrical, in an while provisions on only increase ratio. He died in Bath arithmetical Dec. 29, 1834.