When faced with a lack of any conclusive argument one way or the other, how does
By 'conclusive' argument, I assume you mean some argument that proves, or guarantees, its conclusion. By 'total skepticism' I assume you mean to have no opinion one way or the other at all, or to completely lack any confidence in both the conclusion and its negation. Now, if I understood that right, I think the answer to your question is: by considering arguments that are not conclusive, or don't absolutely guarantee their conclusions. Often, we have arguments that, while not proving or guaranteeing their conclusions, they do provide some good reason to think that the conclusion is true. For example: My dog almost never barks unless there's someone coming; my dog is now barking; therefore, there is someone coming. This is not conclusive, in the sense that it leaves open some possibility that someone is not coming. But it seems unreasonable for me to be totally skeptical, or to have no opinion, on whether someone is coming. Rather, I should be somewhat confident, but not certain, that someone is coming. We have the capacity to believe things to different degrees, and sometimes we are less confident in what we believe than utter certainty. When an argument indicates, but doesn't guarantee a conclusion, the rational response seems to be some confidence, but not certainty, in the conclusion. Total skepticism seems unreasonable in such cases, or at any rate, avoidable. Finally, notice that some arguments would guarantee their conclusions if their premises were true, but we are uncertain about whether the premises are true. For example: All dogs bark; Fido is a dog; therefore Fido barks. I'm not totally certain--and I don't possess any guarantee--that all dogs bark. So this argument isn't conclusive, and even once I understand it and believe its premises (though not with certainty), it seems I should be neither certain in its conclusion nor totally skeptical about it. The conclusion, I should think, is probably true (insofar as the premises are probably true).