High Quality Content by WIKIPEDIA articles! The book An Essay on the Principle of Population was first published anonymously in 1798 through J. Johnson (London). The author was soon identified as The Reverend Thomas Robert Malthus. While it was not the first book on population, it has been acknowledged as the most influential work of its era. Its 6th Edition was independently cited as a key influence by both Charles Darwin and Alfred Russel Wallace in developing the theory of natural selection.