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
At the same time, Marx stressed that capitalism was unstable and prone to periodic crises. He suggested that over time capitalists would invest more and more in new technologies and less and less in labour. Since Marx believed that profit derived from surplus value appropriated from labour, he concluded that the rate of profit would fall as the economy grows. Marx believed that increasingly severe crises would punctuate this cycle of growth and collapse. Moreover, he believed that in the long-term, this process would enrich and empower the capitalist class and impoverish the proletariat. In section one of "The Communist Manifesto", Marx describes feudalism, capitalism and the role internal social contradictions play in the historical process: