Trained in Alcala, Spain and Paris, France before being made professor of theology at Salamanca University in 1532, he is best known in economic theory and theological circles for his writings defending the price differential in usury as compatible with "just price" from the perspective of the Thomists.
He held powerful positions including Confessor of Holy Roman Emperor Charles V and the emperor's representative at the Council of Trent.
Recently, he has been credited by Pierre Duhem with important achievements in dynamics (Etudes sur Léonard de Vinci, t. 3, Hermann, 1913) and is viewed as a forerunner of modern mechanics.