Descartes vs. Hume: From Hume's Perspective

Had I been on the Hume side of the debate, I would have focused on two key areas. One, the issue of Descartes's "perfect entity proves god" theory is a wonderful piece of irrational, circular logic. If I have a concept of a perfect circle, does that mean that the perfect circle placed the concept in my brain? No. I simply have a concept of perfection. Secondly, when the Cartesians made the "Wax Argument", and implied that only through rational thought can you understand that the melted wax is still wax, I would have simply posed the following question: Could you deduce any truth about the wax if you could not perceive it? How could you be rational about something you can't experience?