"Therefore I am not in favour of raising any dogmatic banner. On the contrary, we must try to help the dogmatists to clarify their propositions for themselves. Thus, communism, in particular, is a dogmatic abstraction; in which connection, however, I am not thinking of some imaginary and possible communism, but actually existing communism as taught by Cabet, Dézamy, Weitling, etc. This communism is itself only a special expression of the humanistic principle, an expression which is still infected by its antithesis the private system. Hence the abolition of private property and communism are by no means identical, and it is not accidental but inevitable that communism has seen other socialist doctrines such as those of Fourier, Proudhon, etc. arising to confront it because it is itself only a special, one-sided realisation of the socialist principle."
Marx to A.Ruge