 It is possible to, e.g., exercise moderation with respect to food and drink and yet be covetous and amass money without limits, and the prudence that aids the agent to exercise moderation does not necessarily convince him of the viciousness of covetousness. Virtues are essentially independent of each other. However, Olivi acknowledges the unity of virtues in the sense that in order to become a fully virtuous person, one must acquire all specific virtues. A virtuous agent functions as the unifying factor (Wood 1997, pp. 51–53).