1/Suppose for a moment Karl Marx had not been born.
It is very likely that the 20th century would not have played out as it did. I don't mean to pick on Marx specifically; but individuals induce ideologies, which induce social ties that produce history.
There is nothing particular about Marx's articulation of his ideas that were inevitable; they reflected his observations in the context of his time.
Suppose instead there had been a Dutch writer named Van Halen who published a theory...