Pradip Baksi, « Karl Marx’s Study of Science and Technology », 1996

History itself is a real part of natural history of nature developing into man.

We know only a single science, the science of history. One can look at history from two sides and divide it into the history of nature and the history of men. The two sides are, however, inseparable; the history of nature and history of men are dependent on each other so long as men exist.

… Marx told me with great enthusiasm about the model of an electric engine that had been on show for a few days in Regent Street and that could drive a railway train.

“The problem is now solved,” he said, “and the consequences are unpredictable. The economic revolution must necessarily be followed by a political revolution, for the latter is but the expression of the former.”