What I want to propose here is a quite interesting attempt to show how  ~PSR  undermines itself because it leads to what is known as  Epistemic Nihilism; the idea that there are no epistemic merits or demerits, no epistemic obligations of rationality or showing reasons, and that propositions do not actually entail anything beyond themselves.

If PSR were false, then, as Edward Feser points out, we could no longer say that we believe things for the reasons we think we do, or even that our own faculties of reasoning have nothing to do with any actual standards of truth and logic. We could, however, go further. Deductive arguments could after all end up being completely irrational, since there could in fact be no reason whatsoever why certain conclusion follow from certain premises, or even that no premises entail anything in themselves.

But what is quite interesting is that this is one of the results of epistemic nihilism. Now, if  ~PSR,  then it is also possible that there are in fact no epistemic merits. There really is no such thing as rationality and irrationality, because there are no epistemic facts. You literally aren't required to believe in anything just because it is true or reasonable. In fact, nothing is reasonable on this view.

Of course, the problem with epistemic nihilism is that it is self-defeating and incoherent, because we literally don't have any reason to believe it if it were true, because we don't have any reason to believe ANYTHING if epistemic nihilism were true. Another problem with epistemic nihilism is that, since it denies any epistemic normativity, it is literally meaningless as a position because, at least according to some analytic philosophers, meaning is normative in nature because it may imply other meanings and exclude certain other ones from consideration. This also implies that epistemic nihilism is basically like eliminativist materialism and denies all semantic meaning as well. Yet another problem with this would that  beliefs  have a similar normative structure as meanings and epistemic facts, which means they also imply certain things beyond themselves, namely what else is to be believed and what is not to be beliebed, which entails that epistemic nihilism is quite literally  unbelievable.

I don't know if the above thesis, namely that meaning and beliefs are normative in nature because a certain idea may imply other ideas and the rejection of yet other ones, is compatible with  Aristotelianism-Thomism  and/or  classical theism  and  classical philosophy  (though it seems to be common sense) but if they are, it gives us further reasons to accept PSR.

So basically, I think we may actually be able to make an argument for PSR on the basis that, if  ~PSR  were true, the possibility that  meaning does not exist  and  epistemic nihilism  is true  would be wide open,  which cannot be because they are self-defeating and incoherent, which by implication means that   ~PSR   is self-defeating and incoherent.


The only way out of this would be for a PSR denier to say that  ~PSR  applies only to coherent possibilities that don't outright end up denying rationality wholesale, thus preserving some of the rationality of  ~PSR  (that is, if that position ever even had any  "rationality"  to begin with).


What do you think?

Last edited by aftermathemat (2/13/2018 4:21 pm)