#3 Wootton, Mayr, David Hume, Adam Smith on Feedback Machines and Social Science

The self-regulating machine is not just a crucial step towards a whole series of more advanced technologies. It is the founding concept of modern social science: David Hume’s theory of the balance of trade and Adam Smith’s conception of the market depend on the concept of a feedback mechanism. There is an old debate about why the Greeks and the Romans failed to develop a general theory of economic behaviour; one good answer is that they had no machines with feedback mechanisms, so they lacked an essential tool for thinking about social processes.

David Wootton, The Invention of Science, Penguin 2015

Wootton refers to two technological advances beyond the clock mechanism: Salomon de Caus’s machine for raising water, and Drebbel’s machine for regulating the temperature of chicken eggs, both of which involved feedback mechanisms. Otto Mayr is a fuller source for drawing attention to how much the economic theories of Hume and Smith owed to existing knowledge of self-regulating machines. Hume’s theory of how the supply of money is balanced between countries — in his essay ‘Of the Balance of Trade’ — drew on the analogy of mechanically raising the height of bodies of water. Mayr also points to an interdisciplinary science in formation.

In the evolution of the notion of self-regulation in economics, one can identify the same stages that were traversed in other areas of thought: from an unequal to an even balance; from equilibrium maintained by conscious effort to an equilibrium maintained automatically; from self-balancing capabilities in particular cases to self-regulation as a general interdisciplinary concept.

Otto Mayr, Authority, Liberty and Automatic Machinery in Early Modern Europe, John Hopkins 1986

In fact, there is more of interest here than the mechanical analogies, or the throwaway remark that there was no social science before the invention of self-regulating machines. Wootton is suggesting a causal chain — a science or knowledge ‘motive’ influences the invention of machines, which influences economic theories, which influences the direction of technological and economic development. Tongue in cheek one might say the Industrial Revolution resulted from the unleashed causal forces of 17th century science and machines, not of men, the profit motive, culture, liberty, or ideology. The only serious and certain observation to be made is that the problem of establishing causation is fundamental to all social science. Finding the causes of change in society requires a multidisciplinary approach with a common general method of investigating causes. Multidisciplinarity is done, as it were, in a common cause — the generation of knowledge. It is pure coincidence that someone named Salomon de Caus was a causal link in this chain.