Marx wrote about finance and industry all his life but he only knew two people connected with financial and industrial processes. One was his uncle in Holland, Lion Philips, a successful businessman who created what eventually became the vast Philips Electric Company. Uncle Philips' views on the whole capitalist process would have been well-informed and interesting, had Marx troubled to explore them. But he only once consulted him, on a technical matter of high finance, and though he visited Philips four times, these concerned purely personal mattes of family money. The other knowledgeable man was Engels himself. But Marx declined Engel's invitation to accompany him on a visit to a cotton mill, and so far as we know Marx never set foot in a mill, factory, mine or other industrial workplace in the whole of his life.
~ Paul Johnson