Along with Karl Marx, Engels is considered the father
of communist theory and together they produced The
Communist Manifesto.
Although he dropped out of high school and was sent to work as an
office clerk in Bremen in 1838, Engels got interested in, and
began reading the philosophy of Hegel. He also engaged in literary and
journalistic work and in September of the same year he published
his first work, a poem titled The Bedouin.
Later on when he moved to Berlin, while in the Prussian Army, he
attended university lectures and began to associate with groups of
Young Hegelians.
In 1842, Engels was sent to Manchester, England to work for a
textile firm in which his father was a shareholder. During his
time there, he was appalled at the child labor, impoverished
working conditions and overworked laborers he encountered.
His observations formed the basis for his views on the "grim future of capitalism and the industrial age" and were documented in his first book The Condition of the Working Class in England (1844) - a masterpiece of social observation and important historical record. Lenin described it as "a terrible indictment of capitalism and the bourgeoisie...written in absorbing style and filled with the most authentic and shocking pictures of the misery of the English proletariat."
In 1844 Engels began contributing to a radical journal called Franco-German Annals that was being edited by Karl Marx in Paris. Later that year, Engels and Marx met and they became good friends due to their common views on capitalism and, according to Engels, in virtually "complete agreement in all theoretical fields."
Marx and Engels decided to work together. Where Marx was best at
dealing with abstract concepts, Engels was able to write for a
mass audience. Engels also financially supported the strapped Marx
and his family, giving Marx the royalties from his book, and
arranging for other supporters to make donations. This gave Marx
the time to study and develop his economic and political theories.
It is generally thought that it was Engels, not Marx, who
developed Hegel's idea that the universe is undergoing a constant
process of change and development into the doctrine of
'dialectical materialism.'
Contrary to Hegel's dialectic process of thesis, antithesis and synthesis of ideas, Engel’s dialectic process was one of matter or materialism. To Engels the social conditions of the working class were so appalling that the dialectic process could have only one possible outcome, that of socialism. He felt that the very condition of the working class would drive it to realize that socialism is, and should be, their political ideal.
After the death of Karl Marx, Engels spent his time putting
together and editing the remaining three volumes of Das
Kapital. He also took the time to educate and explain
to the world the concept of Marxism, which he felt would govern
the affairs of men in the foreseeable future.
Another of Engels' interesting contributions was his argument,
using the then current anthropological evidence, to show how the
structure of the family had changed over history.
He stated that the notion of monogamous marriage originated from the necessity within societal class structure for men to control women to ensure their own children would inherit their property.
He argued that a relationship based on property rights and forced monogamy leads to the proliferation of immorality and prostitution. In contrast, a future communist society would allow people to make decisions about their relationships free from any such economic constraints.
Ultimately, the social and political ideals of Karl Marx and Friedrich Engels established them as the philosophical fathers of the communist revolution in a large part of the world.
It is this reason alone that arguably positions them as the most influential philosophers of all time.