1. According to Marin Mersenne (Objections II), Descartes ignores the possibility that a thinking thing might be a body. How does Descartes respond to that by distinguishing his aims in Meditation II and VI?
2. How does Descartes use the distinction between objective and formal reality to respond to Mersenne's claim that the idea of an infinite being might simply be an idea of our own existence expanded infinitely?
3. How does Descartes respond to Mersenne's point that our idea of God (like that of angels or infinite number) is not innate or planted in us by God but learned from others?
4. Mersenne says that Descartes' reasoning is circular, in that he knows that an all-good God exists because he has a clear and distinct idea of him, and he can trust such clear and distinct ideas because an all-good God would not deceive him regarding them. What is Descartes' response to this?
5. How does Descartes distinguish between objective, formal, and eminent existence?
6. How is Descartes' distinction between thoughts and (real) ideas used in his definition of substance?
7. In the third set of objections, Thomas Hobbes suggests that thinking is an activity of corporeal (bodily) substances. What is Descartes' response to this?
8. What is Descartes' reply to Hobbes's claim that our idea of God depends on our imagination of corporeal objects?
9. Why does Hobbes think that his claim that "essence without existence is a fiction of our mind" is an argument against Descartes' discussion of the essence of material things?
10. According to Antoine Arnauld (Objections IV), why is Descartes unjustified in claiming that bodies can't think? And how does Descartes' response depend on his notion of substance?
11. How have Descartes' views about the importance of epistemology and the reconciliation of science and religion influenced modern philosophy?
12. How have Descartes' views about philosophy of mind and the relation of science and mathematics influenced subsequent philosophy?