Ipsius consumptio sive distractio: Money, Interest, and Capital in Thomas Aquinas

The long theological and juridical tradition of monetary theory in the Latin West culminates in Thomas’ interpretation. Moving from Aristotle, Thomas elaborates on the idea of money as an institution, identifying its defining trait as being a measure for the exchange and not the object of the exchange. It is by defining money as something inherently non-appropriable that Thomas derives the condemnation of usury. Usury is no mere sin but a perversion that plagues the social body, favoring unproductive hoarding and diverting energies from a positive circulation of worldly goods. It is in light of Keynes’ rethinking of money that Thomas’ ideas can be identified in their historical and intellectual autonomy, an autonomy that extends both to his predecessors and to his successors. Thomas is no mere mediator of Aristotle, nor can Aristotle’s thought be found verbatim in Thomas’ pages. To trace a more precise demarcation between the Greek philosopher and the Christian theologian comes to the advantage of both.