The present paper deals with Saint Thomas's commentary to Aristotle's De Anima III, in wich we find the famous analogy of light. It is sustained that due to the limitations of the analogy, Saint Thomas is forced to introduce a series of Neo-platonic elements incompatible with Aristotle's philosophy. The author means to explain this "betrayal" to Aristotle's philosophy by one of his most credited commentators. It is concluded that in order to reconcile the pagan world with the Catholic theology, Thomas Aquinas needs to redirect Aristotle through a less economical argument; that is, the introduction of the Intellectus Agens
Mind; Medieval Philosophy; Intellect; Soul; Knowledge