Friedrich Engels1820–1895- Karl Marx and Friedrich Engels The Communist Manifesto (1848), Section 4, paragraph 11 (last paragraph)
Communism is the doctrine of the conditions of the liberation of the proletariat.
Principles of Communism (1847)- Principles of Communism (1847)
- Anti-Dühring, pt. 1, ch. 11 (1877)
- Letter to Marx (4 September 1870)
- Anti-Dühring, pt. 1, ch. 11 (1877)
- Letter to Joseph Bloch (21 September 1890)





