 Malebranche’s reply is subtle and lends itself to multiple interpretations (see e.g., Nadler 1992, 41f; Radner 1978, 107–8, 110–18 and Schmaltz 2000, 73). One way to understand it is to compare it to a causal principle that Descartes invokes in his argument for God’s existence in the Third Meditation. He claims that the objective reality of an idea (such as that of God) must have a cause with at least as much formal reality. Using this principle, he concludes that only a being with infinite formal reality can be the cause of the (infinite) objective reality of my idea of such being. Now, Malebranche is not concerned with causes in this context but with what is required for something to be present to the mind; nevertheless, he is making the same general point: something cannot give what reality it does not have. In perceiving a general idea, such as a circle, we are able to perceive an infinite number of possible diameters (and thus an infinity of possible particular circles). Thus, the general idea of circle contains an infinite degree of reality. If this idea were a modification of my mind, my mind itself would have to be infinite, which it clearly is not.