[Barset]

I mean no disrespect but your post reads like a Marxist version of Art History 101. Feudalism was not "destroyed" by the Black Death alone, nor was the creative impulse controlled by the imperatives of hierarchy, big guys- little guys or of politics. Totalitarianism, the state ownership of even a man's most fleeting thoughts, is a twentieth century historical reality.

[muawiyah]

Classically speaking, the highly structured class system in Europe that developed during the Dark Ages was liberalized during the Black Plague.

Workmen became hard to get for example.

This happened. Now if Marx and Engels used this event as a justification for their theory, that's just tough bananas. There were, during the same period, plenty of other events to disprove their theory.