>Philosophical skeptics may argue that there are no inductive beliefs (knowledge outside deductions or our direct sensations) that can be justified. For example, we don't know that we aren't brains in vats, so we can't say we are justified in believing that we are not.
>
>I argue that this level of skepticism is unwarranted if we have reasonable certainty.

Right but once again, the point of contention isn't so much whether belief is justified provided one has reasonable certainty, its what constitutes reasonable certainty in the first place (especially since "reasonable" or "rational" are often synonymous with "epistemically justified/warranted" in epistemology)- the skeptic agrees that a belief is justified if one is reasonably certain, but claims that inductive or empirical/factual beliefs can never be reasonably certain (since, for instance, we could just be brains in vats or in an ancestor simulation or whatever).

And just as an aside, epistemology seems to have mostly moved on from its obsession with answering the radical skeptic; this was the preoccupation of English-speaking philosophers in the early 20th century- so, Moore, Russell, Wittgenstein, etc- who were responding the idealists and neo-Hegelians who had immediately preceded them. But I think most people consider the radical skeptic to have been well answered, by arguments like Witt's in On Certainty for instance, and so have tended to move on to other problems.

That's not to say there's any harm in rehashing this issue, but it does seem to me that the problem you're attempting to solve has already been adequately dispensed with.