"It may . . . be a subject worthy of curiosity, to enquire what is the nature of that evidence which assures us of any real existence and matter of fact, beyond the present testimony of our senses or the records of our memory." (P 159b)

So Hume will assume we know:

• Relations of Ideas
• The Present Testimony of Our Senses
• The Records of Our Memory

The question is: How can we know (or even have any evidence in favor of) anything else?