Manifesto 2 By Marx & Engels

II.  PROLETARIANS AND COMMUNISTS

In what relation do the Communists stand to the proletarians as a
whole?

The Communists do not form a separate party opposed to other
working-class parties.

They have no interests separate and apart from those of the
proletariat as a whole.

They do not set up any sectarian principles of their own,
by which to shape and mould the proletarian movement.

The Communists are distinguished from the other working-class parties
by this only: (1) In the national struggles of the proletarians
of the different countries, they point out and bring to the front
the common interests of the entire proletariat, independently of
all nationality.  (2) In the various stages of development which the
struggle of the working class against the bourgeoisie has to pass
through, they always and everywhere represent the interests of the
movement as a whole.

The Communists, therefore, are on the one hand, practically,
the most advanced and resolute section of the working-class
parties of every count