The most well-known theory is the Malthusian theory of population. Thomas Robert Malthus wrote his Essay on Principle of Population in 1798 and modified some of his conclusions in the next edition in 1803. The rapidly increasing population of England encouraged by a misguided poor Law, distressed him very deeply. He feared that England was heading for a disaster. and he considered it his
solemn duty to warn his countrymen. He deplored “the strange- contrast between overcame in breeding animals and carelessness in breeding me.

His theory is very simple. To Elise own words: By nature human food increases in a slow arithmetical ratio: man himself increases  in a quick geometrical ratio unless want and vice stop him.

1,200,000,000,000,000,000,000, and if they stood shoulder to shoulder about one in every 150,000 would be able to find a perching space on the whole surface of the globe. According to Huxley’s estimate, the descendants of a single greenfly, if all survived and multiplied, would. at the end of one summer, weigh down the population of China! Human beings are supposed to double every 25 years.and a couple can increase to the size of the present population in 1,750 years,

Malthus asserted that the population of a country tends to double every twenty-five years (as it was actually happening in the American Colonies and the U.K. at that time), but the food supply could be increased much less rapidly. In fact, Malthus observed that the population tended to increase at a geometric rate (2. 4, 8. 16,32,64, etc.t, but the food supply tended to increase at an arithmetic rate (2, 4, 6, 8, 10, 12). Thus at the end of two hundred years population would be to the means of subsistence as 259 to 9; in three centuries as 4,096 to 13 and in two thousand years the difference would be incalculable.Therefore, Malthus asserted that the population would ultimately.