In commenting on the works of Aristotle, most arts masters saw their task as two-fold, viz., that of explaining the littera or literal meaning of Aristotle's text, and then (usually in a separate work) of identifying and trying to resolve the philosophical questions raised by it. Seneca was an authority in moral philosophy and theology throughout the Latin West during the entire medieval period. The controversy to which John Buridan refers is one he narrated between Aristotle and Seneca on the question of whether happiness consists in the act or the mere possession of virtue. This chapter explores how Buridan use Senecan insight to perfect Aristotelian moral philosophy. Seneca should not be interpreted as saying that virtue cannot be increased or diminished no matter where it is found, but only virtue in its most perfect and complete state, which is wisdom.