ABSTRACT
This chapter explores the historical scholarship that culminated in the modern theory of markets. Understanding the how markets operate to determine prices is of central importance to the discipline of economics. The primary question for the ancient and medieval scholars was not to understand the mechanics of markets, but to apply principles of justice to exchange between individuals. For ancient and medieval scholars, individual exchange was an element of broader social relationships among people, so they tended to emphasize the ethical standards that should govern those relationships. When the medieval Scholastics considered questions of value, they drew on Aristotle's concept of commutative justice, one of two types of justice he described in the Nicomachean Ethics. Odd Langholm quoted an unidentified medieval Romanist who explained, 'a thing is worth as much as it can be sold for'. While this is consistent with what modern economists would say, different interpretations emerged at the time.
