Was Hume a Skeptic?

I hear skeptical atheists (as opposed to the logical variety) laud David Hume, the great 18-century Scottish philosopher, who is thought to have been a thoroughgoing skeptic. Hume famously wrote that "reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them." So I wonder whether these atheists would endorse this passage from Hume's An Enquiry Concerning Human Understanding, section 12, part 1, in which he criticizes Descartes's proposed path to knowledge:

There is a species of scepticism, antecedent to all study and philosophy, which is much inculcated by Des Cartes and others, as a sovereign preservative against error and precipitate judgement. It recommends an universal doubt, not only of all our former opinions and principles, but also of our very faculties; of whose veracity, say they, we must assure ourselves, by a chain of reasoning, deduced from some original principle, which cannot possibly be fallacious or deceitful. But neither is there any such original principle, which has a prerogative above others, that are self-evident and convincing: or if there were, could we advance a step beyond it, but by the use of those very faculties, of which we are supposed to be already diffident. The Cartesian doubt, therefore, were it ever possible to be attained by any human creature (as it plainly is not) would be entirely incurable; and no reasoning could ever bring us to a state of assurance and conviction upon any subject. [Emphasis added.]

Hume went on to write:

It must, however, be confessed, that this species of scepticism, when more moderate, may be understood in a very reasonable sense, and is a necessary preparative to the study of philosophy, by preserving a proper impartiality in our judgements, and weaning our mind from all those prejudices, which we may have imbibed from education or rash opinion. To begin with clear and self-evident principles, to advance by timorous and sure steps, to review frequently our conclusions, and examine accurately all their consequences; though by these means we shall make both a slow and a short progress in our systems; are the only methods, by which we can ever hope to reach truth, and attain a proper stability and certainty in our determinations. 

To which I say: why call that skepticism? It's simply the exercise of reason, premised on the principle that reality is intelligible if we exert the effort we call reasoning. It is no argument against the efficacy of reason to point out that in empirical matters we can't be sure what we will discover tomorrow. The world in all its richness awaits our discovery. That this cannot be accomplished in a day is of no earth-shaking importance.

I'll go further by saying that I can't see how Hume qualifies as any kind of skeptic at all. When he wondered how we can believe that objects don't cease to exist when we aren't looking at them, it seems to me that he wasn't saying that therefore we shouldn't believe it. Rather, he was showing that this is what philosophical speculation gets you: thoughts that conflicted starkly with everyday life. He did not think we should give up our everyday reasoning as a result because we couldn't get on without it. That's not skepticism.

It is true that Hume wrote that reason is "the slave of the passions," but that's a different matter. He meant that reason couldn't tell us what ultimate ends are proper to pursue. But he did believe that reason could tell how best to achieve the ends that we seek; he had a purely instrumental, and not a substantive, conception of reason. (I think he was mistaken; see Roderick T. Long's Reason and Value: Aristotle versus Rand for details.) Maybe that qualifies him as a moral skeptic, or better, agnostic, but it is not general epistemological skepticism. For Hume, human beings are capable of gaining the knowledge needed to live life, and that's saying something.

Skeptical atheists need to look elsewhere for a hero. They'll not find one in David Hume.