@cofty: The philosophy that underpinned Fascism (National Socialism and actual Italian Fascism) is Marxism.
Both Hitler and Mussolini quoted Marx and used the ideology as an underpinning for their own and then modified it slightly. Mussolini considered himself a Marxist, and he described Marx as "the greatest of all theorists of socialism." Hitler himself declared that national socialism was based on Marx and argued that the other socialists of the day were basically corrupted socialists, which is the same argument that the Bolscheviks said about the Menscheviks, but they're all still socialists and fought together against the establishments of the day, only disagreeing with each other once it became time to rule (which is typical for all socialists, to date).
Similar argument that JW's make when saying that other religions are "Christendom" and not true Christians or Martin Luther saying that the Pope corrupted Christianity.