I have heard many explanations for why and how scientific thought arose in the late Middle Ages, ultimately blooming fully in the Renaissance. But one of them was not that science was linked to the emerging money-based economy of the 14th century. Joel Kaye puts forth and defends the fascinating thesis that the proto-scientific thinkers of this period were strongly influenced by the real-world practice of market exchange.
For those of us who are not medieval scholars, it is difficult to imagine how people of the 14th century conceptualized their society and the universe. Although Kaye's book is intended for an audience of his peers, he does a remarkable job of making it comprehensible to non-specialist readers (although he does liberally quote the original Latin in the footnotes as if you have a clue what it says). Overall, this book is highly readable and gives intriguing insight into the philosophical connections between science and economics. I'll give it a "+".
Money as a medium of exchange came into popular usage during the late 13th century. Given its current ubiquity, it is difficult to understand what an epic change the monetization of Europe represented. Scholars of the period began to comment on the nature of money, and to explore its deeper meaning. These scholars came from several disciplines, such as law, ethics, and religion. Many were University administrators, who thus had connection to both the scholarly life and to the setting and spending of budgets. Although as scholars, they tried to ground their ideas in universal principles, Kaye argues convincingly that they were influenced by their mundane, personal participation in the emerging market economy.
The seed for a new philosophy of the market came largely from Aristotle, who first articulated the idea of a dynamic marketplace, where prices are driven by supply and demand, and money serves as a neutral medium to equate differing objects in proportion to their value. Some of the earliest texts relevant to Kaye's thesis are commentaries on Aristotle's works, reviving these ancient ideas and applying them to the present.
One key concept was that of "geometric" equivalence rather than "arithmetic" equivalence. This actually came from a legal idea of distributive justice, in which greater service or value brought proportionally greater reward ("arithmetic" would mean that all received a numerically equal reward). Since people are unequal in their service, the rewards of common goods by a central authority must also be unequal. It was a short extension to understand that different people might also get a different price for the same goods in an open market.
Other new ideas began to spring forth, some of them disturbing to the established order. What is the just price for something? Surely it is the one that establishes correct geometrical equivalence, but who should decide that? At first, scholars felt comfortable claiming that a judge could be relied upon to establish the "true" value of something-- for they could not imagine an ordered system without some sort of intelligent agent directing it.
The problem was, the market was already happily functioning by itself in food stalls, cobbler's shops, and taverns every day. It seemed to be good for society, but was it moral? If not, how it be such an obvious boon? Worse, new classes of economic agents were arising-- middlemen who "added value" to things they bought, then sold them for a higher price. If the added value was nothing more than carrying them from a location of abundance to a location of scarcity, could they charge for that? How much? When did these sorts of acts start to border on the sin of usury?
Money began to cause other, more subtle shifts in perception also. Slowly, the concept of a perfect "balance point" representing the just price gave way to the concept of an acceptable range of prices. Maybe the market really could be an ordered system that functioned without an intelligent agent (ie, God)-- a truly radical idea. Furthermore, people began to explore the idea that money itself might have value, beyond being a convenient medium of exchange.
Paralleling these shifts, and related to them, came a revolution in the practice of measurement. If money was a medium for creating equivalence between dissimilar objects (or between a seller's object and the buyer's "need"), then essentially it was also serving as a standard of measurement. This opened up debate about what was measurable, and how one might agree on relative values of qualities. Like many new principles, this one was overapplied. People were soon measuring much more than simple things like length and mass-- they measured "whiteness" and even seeming intangibles like Christ's love and a servant's devotion. It was a veritable measurement frenzy.
With the stage set in this way, it is easy to understand how proto-scientific ideas could emerge. How shall we compare the speed of an object to its distance travelled? Early measurement enthusiasts invented what were essentially Cartesian plots to describe quantitative relations between two qualities. They began to understand that discrete objects (such as coins) could represent continuous variables (such as value), which allowed the conception of a continuous number line populated by discrete integers, fractions, and even irrational numbers.
(Shunned by medieval thinkers, irrational numbers were back, re-outfitted as morally acceptable in the new world of proportions. Although they cannot be expressed as the ratio of integers, irrational numbers are inevitable once you start drawing triangles to show relations between qualities. Several key thinkers pointed out these numbers' prevalence-- there are more of them than rationals-- and managed to fit them into the emerging philosophies as primary actors).
With some new mathematical tools and the measurement frenzy underway, scientific discoveries were inevitable. Kaye's linking of this new way of thinking to the development of a monetary economy over the 14th century is fascinating and convincing. It is one more example of the real world leaping ahead of our ability to analyze it, so that we only fully grasp the implications of what we've done much later. Who knew what the convenience of using a few copper coins to represent the cost of a horse would turn into?
Copyright © Kim Allen 2002
