THE ALLURE OF ANALOGIES FROM PHYSICS

Philip Ball, the author of: ”Invisible: The Dangerous Allure of the Unseen” and many books on science and art, posts HERE

“It might seem unlikely, even insulting, to suggest that people can be regarded as little magnets or particles dancing to unseen forces. But the danger is not so much that “social physics” is dehumanizing. Rather, it comes if we do not use the right physics in thinking about society.

Physicists have learned that natural systems can’t always be described by classical, equilibrium models in which everything reaches a steady, stable state. Similarly, social modelers must beware of turning society into a deterministic Newtonian machine by applying inappropriate physical models that assume society has only one way of working properly. Society rarely finds equilibrium states, after all. Social physics needs to reflect that very human trait: The capacity to surprise.

Both the attraction and the pitfalls of a physics of society are illustrated in economics. Adam Smith never actually used the term “market forces,” but the analogy was clearly in his mind. Noting how market prices seem to be drawn to some “natural” value, he compared this to the effect of gravity that Isaac Newton had explained as an invisible force a century earlier. Smith also said in his seminal Wealth of Nations that an “invisible hand” maintains equilibrium in the economy.

Smith was not alone in following Newton. Newtonian clockwork mechanics were, at the time, regarded as the model to which all understanding of nature should aspire, perhaps even including the mechanics of the human body and of society.

Comment

Looking through my desktop I have found several draft posts that I do not remember posting as my replies. As the above is very relevant to my thinking and published writing, I shall publish my comments here.

The assertion that “Noting how market prices seem to be drawn to some “natural” value, he compared this to the effect of gravity that Isaac Newton had explained as an invisible force a century earlier”, is not quite what Adam Smith said, and the difference is important.

In a paper I wrote on this very subject in 2015, I argued:

“All bodies with mass exert gravitational pull on all others, but not all of them have the same mass or exert the same degree of mutual attraction that draws them physically towards each other or holds them in regular orbits. It does not follow that Smith’s use of gravity as a metaphor described an observed or plausible relationship between Market and Natural prices, either of which were sometimes above or sometimes below the other’s prices, as described in WN.

Smith’s metaphoric use of gravity was not intended as a scientific statement about the physics of a gravitational attraction embodied in prices. He ex- presses his reservations twice, first writing: “the natural price, therefore, is as it were, the central price, to which the prices of all commodities are continual- ly gravitating (WN I.vii.15: p.75) and then repeats it two pages later: “the mar- ket price of every particular commodity is in this manner continually gravitat- ing, if one may say so, towards the natural price” (WN I.vii.20: 77). Ultimate- ly, production costs (as defined) must tend to be met by market prices, inclu- sive of the participants’ profits, if economic production is to commence and continue. Natural and Market prices do not exhibit the definable physics of ‘mass’, nor do yhet operate in a definable or predictable order. If Smith’s metaphoric references were scientific statements, Newtonian or Epidoclean, Smith would have left out his semi-apologetic qualifiers because they would have been inappropriate, bearing in mind also that not all of his readers were expected to have studied classical or philosophical history. 

Smith generalises, in the round quite heavily, his metaphoric assertions about Natural and Market prices. Indeed, in the immediately following chapters he goes into detail about metaphorical gravity relationships: “yet sometimes par- ticular accidents, sometimes natural causes, and sometimes particular regu- lations of police, may, in many commodities, keep up the market price, for a long time together, a good deal above the natural price.”

Extract from: Kennedy, G. Adam Smith’s Use of the ‘Gravitation’ Metaphor, published in Economic Thought 4.1: x-xx, 2015.