Indefensibility, Skepticism and Conceptual Truth

It is true of many truths that I do not believe them. It is
equally true that I cannot rationally assert of any such truth
that it is true and that I do not believe it. Such a claim is
indefensible, i.e. for internal reasons unable to convince. I
claim that such is the skeptic's predicament, trying to
convince us to bracket knowledge claims we have good
grounds to take ourselves to be entitled to. An analysis of
skepticism as an epidemic rather than epistemic challenge
will shed new light on what it is to doubt a proposition and
provide us with an analysis of conceptual truths as those
which cannot rationally be doubted.