Empirical Science Challenges the Validity of Marxism

He argued that as a scientific enterprise, it was incumbent upon Marxism to continually test the accuracy and reliability of its factual claims. Furthermore, the canons of empirical science required that Marxism be prepared to confirm or disconfirm its predictions against the evolving reality of the modern world.... In almost all the cases to which Bernstein alluded, he claimed that existing data, and measurable projections, tended to disconfirm the empirical claims and substantive predictions of the founders of revolutionary Marxism.

--A. James Gregor, Marxism, Fascism, and Totalitarianism: Chapters in the Intellectual History of Radicalism (Stanford, CA: Stanford University Press, 2009), 49-50.