It's probably hard for us Marxists to admit how much our philosopher king was changed by reading Ure and Babbage, stalwart defenders of laissez faire. But Marx took over 70 excerpts in long hand written notes from Babbage in 1845. It may well have been a turning point in his thinking--though this has not been commented on in English as far as I know. Maybe the Hegelian dialectic is easier to understand than the operation of the difference engine, so the problem of philosophical foundations has remained central. His first major economic work Poverty of Philosophy shows already a deep appreciation of how the machine age had rendered Proudon's ideas of socialism antiquated (see chapter 2, section 2); in a similar vein, Marcuse argued more than 100 years later on the basis of very little evidence (but the attempt to think his time in terms of its technological possibilities is interesting) that automation of the tasks of operators and assembly line workers meant the development of the working class henceforth as sophisticated machine makers and technicians who would suffer none of the physical privation of industrial work and achieve integration (despite continued 'alienation') in the capitalist system. Yet now machine design is being rapidly automated while the machine operator has hardly disappeared.
At any rate, the influence of Ure and Babbage on Marx is clear.
Two great influences on Marx were Babbage's Economy of Machinery and Manufacture and (to raise another set of concerns) the anti Ricardian deeply conservative Richard Jones' political economy of historical rent systems (to which Marx devotes a whole chapter in Theories of Surplus Value because it is the last work to have grasped clearly the historical distinctiveness of capitalism in terms of its relations of exploitation--GA Cohen hardly mentions him, just as he ignores the Ethnological Notebooks). yet is there a *single* history of economic thought in which both these giants of the 19th century are discussed in any detail (Babbage and Jones)! Marx would have surely been disappointed. Marx learned much from this empirical historian of labor systems as well as the great student of modern technology.
He surely wouldn't have wanted to resolve the question about the primacy of the relations over the forces as an abstract philosophical question without a careful empirical specification of each.
yrs, rakesh