I think he would start by talking about being deceived, that regardless of Hobbes' belief that he knows when we are awake, there could be an evil demon deceiving Hobbes. Descartes would likely discredit Hobbes's claim that he is capable of having more concrete and recurring thoughts while awake, as opposed to when he is asleep. But Descartes says that he has had dreams in which while he is asleep he does exactly the same thing as he does while he is “awake”. Hobbes also experienced this, but some cannot relate to this. Even then, where Hobbes's concrete shortcomings are that make him confident that he knows when he is awake and when he is asleep, he claims to have "faith" that he is satisfied with this. But Descartes does not seem to have truly thought about abandoning all opposing ideas and ignores his own proof of a perfect being. The refutation of Descartes is becoming less and less