Value-form
The Western Left academics are nowadays very happy to talk about "varieties of capitalism", but talking about "varieties of socialism" remains almost an absolute "no-no". Most Marxists continue to believe in "only one" (Marxian) socialism: either that, or nothing at all. "Either" a society or movement conforms to the true concept of socialism, "or" it does not; and if it does not, it "cannot be" socialism. However, precisely "because" there are many different Marxist beliefs about socialism, Marxists cannot agree among themselves whether Soviet-type societies were socialist, capitalist, or something else. Some countries meet with the moral expectations which Marxists have, and others do not.Originally Marx and Engels themselves had heckled the advocates of "true socialism", but later Friedrich Engels and Karl Kautsky promoted Marxist socialism as the one and true "scientific socialism" within the Socialist International. When he was 43 years old, Lenin stated: "The Marxist doctrine is omnipotent because it is true". Lenin's Communist International (a deliberate split with the social democrats) adopted Marxist socialism as its official political doctrine.
Karl Marx
Marx's theories about society, economics and politics – collectively understood as Marxism – hold that human societies develop through class struggle. In capitalism, this manifests itself in the conflict between the ruling classes (known as the bourgeoisie) that control the means of production and the working classes (known as the proletariat) that enable these means by selling their labour power in return for wages. Employing a critical approach known as historical materialism, Marx predicted that, like previous socio-economic systems, capitalism produced internal tensions which would lead to its self-destruction and replacement by a new system: socialism. For Marx, class antagonisms under capitalism, owing in part to its instability and crisis-prone nature, would eventuate the working class' development of class consciousness, leading to their conquest of political power and eventually the establishment of a classless, communist society constituted by a free association of producers. Marx actively pressed for its implementation, arguing that the working class should carry out organised revolutionary action to topple capitalism and bring about socio-economic emancipation.