Martín de Azpilcueta: The Spanish Scholastic on Usury and Time-Preference

Martín de Azpilcueta and his fellow Spanish Scholastics writing and teaching at the University of Salamanca during Spain’s Golden Age are rightly pointed to by historians of economic thought as being major contributors toward, if not outright founders of modern economic theory. Among these is the theory of time-preference for which Azpilcueta has repeatedly been given the credit for discovering. However, this discovery is a curious one given how the same man, Azpilcueta, condemned usury in general during his whole life. If Azpilcueta did in fact discover this theory and fully understand its implications, we would reasonably expect him to have questioned his support for the ban on charging an interest on a loan. This paper, therefore, challenges the claim that Azpilcueta understood and revived time-preference theory and shows how his understanding was much more nuanced, and, at times, inconsistent.