Is the fact/value dichotomy itself a fact or a value?

If it is a fact then it cannot function as the source of a normative claim. After all, you can’t get an ought from an is. So the adherent of the view that the fact/value dichotomy is itself a fact can offer no reason why it ought to guide our moral reasoning—at least, he cannot do so without falling into contradiction.* If the fact/value dichotomy is a fact then on its own terms we cannot derive from it any moral obligation, including the obligation to heed the fact/value dichotomy as any sort of “limiting principle” to our conception of morality. If it is a fact then it is of no moral consequence.

If the fact/value dichotomy is a value then by its own terms it can’t be a fact, nor can it be derived from facts; it can’t be validated empirically and so by definition can’t be a “positive claim.” So the adherent of the view that the fact/value dichotomy is itself a value enjoins us to believe a claim about the nature of moral epistemology that by his own standard cannot be factual. It cannot be grounded empirically and so cannot be the object of scientific inquiry or provide a posteriori justification for any belief. If there is no empirical basis for believing the fact/value dichotomy, then the burden is on the empiricist to explain how it is true. And if it cannot provide a posteriori justification for any belief, it cannot do so for any specific belief about whether a given proposition is a fact or a value: after all, whether a proposition is a fact or a value is a matter of fact, not of value.

Conclusion: if this criticism is valid, then the fact/value dichotomy is seriously self-undercutting and should be abandoned.

* Nor, for that matter, can he say how the fact that there are facts creates any moral duty whatsoever for us to affirm facts. It would appear that his position actually bars him from doing so. So our attitude toward facts, itself not being a fact, must be a value with no basis in fact.