 There is an alternate division of ideas worth noting. In the Third Meditation, after having introduced the tripartite division of innate, adventitious, and factitious ideas, Descartes continues to entertain the possible origins of the contents of his ideas. His analysis turns on the principle that an effect can never be greater than its cause, which is underwritten by the self-evident principle that something cannot come from nothing. He says: “And although one idea may perhaps originate from another, there cannot be an infinite regress here; eventually one must reach a primary idea, the cause of which will be like an archetype which contains formally (and in fact) all the reality (or perfection) which is present only objectively (or representatively) in the idea.” (AT VII 42; CSM II 29) Here, Descartes introduces the notion of a primary idea. The import of this notion is that the contents of some of his ideas may have their origin in things located “outside” his mind—that is, in things that exist independently of his mind. 