Seminar: « Radical Uncertainty : History, Theories, Concepts »

Risk in economic activity in Thomas Aquinas

Thomas Aquinas (c. 1225-1274) is the medieval author whose economic contribution is the most important in terms of size, posterity, the diversity of the operations he describes and the changes he made possible in our understanding of economic activity. Although he did not formulate a unified theory of risk, the different situations he described can be translated today by the existence of random variables, or functions that range from states of the world to a set of possible consequences, which corresponds to the broadest and most general definition of risk. Thomas wrote well before Knight's (1921) distinction between risk, which is calculable, and uncertainty, which is not. It is, however, debatable how best to capture what he describes and the advantages and disadvantages of using the terms risk and uncertainty. However, we can discuss the most appropriate way of describing what he describes and the advantages and disadvantages of using the terms risk and uncertainty. Thomas himself offers a vast lexicon of risk, mobilising the notions of probability (in the ancient and medieval sense, where probable is opposed to certain), frequency, estimation (sometimes taking on the meaning of approximation), prudence (which is a cardinal virtue, but whose similarity with the contemporary statistical meaning is striking), or danger (we can observe an evolution in Thomas, who begins to present certain costs, such as the transport operated by the merchant, as expenses, before presenting them from the point of view of danger). We can also draw on Thomasian vocabulary, which is found outside economic texts, to synthesise all the dimensions of economic risk, such as the notion of ‘arduous good’ (bonum arduum), which is a good that is difficult but possible to achieve and future. A text-by-text and activity-by-activity analysis reveals a risk map, followed by different risk typologies that can be cross-referenced. The result is a dynamic structure of economic risk. This survey of risk is of interest not only in the history of ideas, but also in contemporary economic analysis, because although the context has changed, the fundamental economic operations and the risks they entail remain the same.

Pierre Januard est Professeur aggregatus à l'Université Pontificale Saint Thomas d'Aquin - Angelicum (Rome)

https://univ-lille-fr.zoom.us/j/93683324658?pwd=ncX6utf0U0xLik3cPdzuYgoRmAw31H.1