Sinnott–Armstrong's moral scepticism

Walter Sinnott-Armstrong's recent defense of moral skepticism raises the debate to a new level, but I argue that it is unsatisfactory because of problems with its assumption of global skepticism, with its use of the Skeptical Hypothesis Argument, and with its use of the idea of contrast classes and the correlative distinction between "everyday" justification and "philosophical" justification. I draw on Chisholm's treatment of the Problem of the Criterion to show that my claim that I know that, e.g., baby-torture is wrong, is no more question-begging than Sinnott-Armstrong's denial that I know this.