Friedrich Engels (November 28, 1820 - August 5, 1895) was a German industrialist, social scientist, author, political theorist, philosopher, and father of Marxist theory, working in close collaboration alongside Karl Marx. In 1845, he published The Condition of the Working Class in England, based on personal observations and research. In 1848, he produced with Marx The Communist Manifesto and later he supported Marx financially to do research and write Das Kapital. After Marx's death Engels edited the second and third volumes. Additionally, Engels organized Marx's notes on the "Theories of Surplus Value" and this was later published as the "fourth volume" of Capital.
Engels is commonly known as a "ruthless party tactician", "brutal ideologue", and "master tactician" when it came to purging rivals in political organizations. However, another strand of Engels’s personality was one of a "gregarious", "big-hearted", and "jovial man of outsize appetites", who was referred to by his son-in-law as "the great beheader of champagne bottles.”
Anti-Dühring, Herr Eugen Dühring's Revolution in Science is a detailed critique of the philosophical positions of Eugen Dühring, a German philosopher and critic of Marxism. In the course of replying to Dühring, Engels reviews recent advances in science and mathematics and seeks to demonstrate the way in which the concepts of dialectics apply to natural phenomena. Many of these ideas were later developed in the unfinished work, Dialectics of Nature. The last section of Anti-Dühring was later edited and published under the separate title, Socialism: Utopian and Scientific.