Since the Middle Ages, the rudiments of a functioning credit system have been necessary conditions for the expansion of commercial capitalism. […] It is all the more surprising, then, that it was not until the end of the eighteenth century that a sufficiently systematic discussion of banking, capital, and credit mechanisms got underway. This may be due to a delay in the emergence of a systematic science of economics, which was notoriously late in catching up with manifest business practices; but it may also have owed something to a certain theoretical resistance to the fact that a genuinely capitalst structure — one that trades with credit, assets, prospective profits, and hence with time — could no longer be directly translated back into elementary exchange and balance relations. Though people still assumed that there was a balancing dynamic at work in the market, the constant circulation of debt, credit, and capital they observed seemed to contradict this assumption, and they were evidently alarmed by the wide-ranging impact of the economic decisions and actions being taken.
Joseph Vogl, The Specter of Capital (Stanford: Stanford University Press, 2015), p.41.