Stating the PSR as "there is a sufficient reason or adequate necessary objective explanation for the being of whatever is and for all attributes of any being" (Bernard Wuellner, Dictionary of Scholastic Philosophy, p. 15), its usual denial, on which I will focus, consists in the denial of "whatever" and "any", by specifically excluding the being and attributes of the universe itself.

That kind of denial may be ad hoc, but it is not subject to the retorsion argument. Because the deniers' issue with Feser's statement that "We also suppose that our cognitive faculties track truth and standards of rational argumentation" is only with its scope. Noting that, in a correspondence theory of truth, truth is the conformity of mind to reality, holding PSR amounts to assuming that reality is ultimately rationally explainable, while the denial of PSR amounts to assuming that reality is rationally explainable up to a point, usually the existence and laws of the universe, where we find a brute fact [1].

The issue is: why should someone assume that reality is ultimately rationally explainable? This may be perceived more clearly if we examine the alternative interpretation of observed facts that a materialistic evolutionist could propose instead of that based on the PSR, consisting of points M1 to M3:

M1. Brute fact: the universe exists and works causally according to mathematically expressible laws.

M2. The rationality of our mind, i.e. the agreement between the way it understands reality and the way the universe works, was selected by evolution. Because, on seeing the branches of a bush moving in windless weather:
- the walking-talking apes who thought the movement had a cause got ready to fight or flee, and thus survived and were able to pass on their genes.
- the walking-talking apes who thought the movement did not have a cause did nothing, and were killed by a rival tribe or a predator.

M3. At some point, some of the walking-talking apes that were so evolutionary successful because, among other things, the way their mind worked conformed to the way the universe worked, got the big picture the other way round, and thought that it was the way the universe worked which conformed to the way their mind worked. That would have had no practical consequence, but some of them went even further, and claimed that their mind was able to explain reliably not only the way the universe worked, but even why there was a universe! And the apes called that statement the Principle of Sufficient Reason, and they rejoyced greatly.

"Hey, walking-talking ape, who do you think you are?"

Note that your statement "And if we refuse to give a reason why our faculties should have their causes or explanations, this would apply to any of our specific beliefs, including our denial of PSR." can be turned around, so that our holding of PSR is a fact for which we should be able to give a reason. I posit that holding the PSR, i.e. that reality is ultimately rationally explainable, is rationally based on the assumptions that Subsistent, Ultimate Reality is Logos i.e. Reason, that human reason is created in the image of the uncreated Logos, and that the universe was created according to reason [2].

[1] Quotes of instances of this view by Hume, Russell and Sean Carroll are in an article in a blog of mine:
http://defeyrazon.blogspot.com/2015/08/thesis-1-holding-psr-is-equivalent-to.html

[2] Here "created" can be replaced by "emanated" to allow panentheism as an alternate entry point to be later corrected to theism by way of the PSR. Notably, this was precisely the intellectual road travelled by the late Scott Ryan, as can be seen on pp. 353-355 of his 2003 book:
http://www.scholardarity.com/wp-content/uploads/2012/06/Objectivism-and-the-Corruption-of-Rationality-Scott-Ryan.pdf
 

Last edited by Johannes (6/12/2016 11:52 pm)

RBrad wrote:

But wouldn't the problem with this be that we would need some reason why, if PSR is not true in general, it should hold for our cognitive faculties? I think you're right in thinking people denying PSR wouldn't hold that it always fails to hold. But if PSR is not true in general, why should it be true regarding our rationality? What about our faculties would exclude them from the domain in which PSR fails to hold?

The issue in the deniers' case is not with our faculties, specifically our rationality, but with reality. Reality within the universe conforms to our rationality (actually, for the materialistic evolutionist, it is the other way round), but that does not imply that the universe as a whole does too. If you feel fine with that, you may assume that it does, and there's nothing wrong with that. The denier just finds your assumption not compelling and probably also its explicit consequences (which I posit are also its implicit assumptions) not comfortable.

RBrad wrote:

Your points (M1-M3) are well made. But it seems to me that we could say, "Yes, but how do you know you believe M1, M2, or M3 for some reason, as opposed to no reason whatsoever, which we cannot exclude as a possibility if PSR is false?"

Since the guy holding M1-M3 is a PSR denier, he doesn't really need a reason for holding them. He can just say "I feel better holding that than holding the PSR".

RBrad wrote:

Well it seems we would be able to give a reason for accepting PSR, namely that rejecting it is self-defeating.

The position of limited PSR denial is not actually self-defeating, since it rejects PSR only as it applies to the ultimate explanation of the universe, not to explanations of facts within the universe. Sure enough that position is question-begging, as pointed out by Prof. Feser in this article:

http://edwardfeser.blogspot.com/2014/10/della-rocca-on-psr.html

where the kind of PSR denial I am focusing on is (1), which clearly is begging the question against PSR.

Feser says:

"So, Della Rocca’s argument is that there seems no cogent way to accept EAs at all without accepting PSR.  The implication seems to be that we can have no good reason to think anything is explicable unless we also admit that everything is."

Actually we have extremely good reasons to think that all facts around us are rationally explainable: empirical physical evidence. The issue is: why should we assume that the ultimate fact, the existence of the universe, is also rationally explainable?

Sure enough, holding PSR is a wholly consistent position which avoids making any ad-hoc assumptions (*), but again: why should that feature guarantee that it actually applies to ultimate reality?

Thus, the situation is exactly as described by Feser at the end of the article: "Why, it’s almost as if such philosophers don’t want the PSR to be true, and thus would rather not have their prejudice against it disturbed." Because PSR, as "P" in "Principle" denotes, is an assumption, an axiom, and as such it can be adopted or rejected, just like the Continuum Hypothesis in conjunction with ZFC, with the main motive for going either way being how comfortable the person feels with the presuppositions implicit in, or amounting to, that assumption. And the presupposition implicit in the assumption that reality is ultimately rationally explainable is clearly that Ultimate, Subsistent Reality is Reason, of which our reason is an image.

(*) It just came to my mind that the PSR denier might even argue, or try to argue, that the assumption that reality is rationally intelligible through and through is just as ad-hoc as the assumption that it is rationally explainable only up to a point where we find an unintelligible brute fact, only more elegant.

Last edited by Johannes (6/13/2016 11:34 am)

RBrad wrote:

I know that, in their view, they’re not denying PSR ever holds. Rather, they are denying it everywhere and always holds. But this just raises the question: if PSR does not hold for all of reality, what reason could we have for thinking it holds for some subset of reality (more specifically, a subset that does not exclude our faculties)? Any reason would look suspiciously like PSR.

As I said in my previous post, "we have extremely good reasons to think that all facts around us are rationally explainable: empirical physical evidence."

To illustrate this point, I will quote from an article by Frank Wilczek, Professor of Physics at MIT and Recipient of the 2004 Nobel Prize in Physics, on the discovery of the Higgs boson:

"Why does it matter?

The discovery of the Higgs particle is, first and foremost, a ringing affirmation of fundamental harmony between Mind and Matter.  Mind, in the form of human thought, was able to predict the existence of a qualitatively new form of Matter before ever having encountered it, based on esthetic preference for beautiful equations.

We plumb the depth of that Mind-Matter harmony if we meditate on the challenge the Higgs particle discovery posed."

https://www.bigquestionsonline.com/2013/04/22/why-does-higgs-particle-matter/

RBrad wrote:

As I said in my previous post, "we have extremely good reasons to think that all facts around us are rationally explainable: empirical physical evidence."

But that's question-begging, because it's assuming our faculties that lead us to believe there is good empirical evidence have explanations, which is exactly what's at issue.

Could you please clarify what precisely you mean that I am assuming has explanations? A literal reading of your text points to option A, but the context seems to point to option B (and of course, you might be meaning yet another option):

A. Our faculties, particularly our rationality, in themselves.
B. The correspondence between our rationality and the way the universe works.

Both possible meanings have explanations in both the spiritual-rational position and the materialist-evolutionist position, although of course the respective explanations are different, and the explanation offered by the second position for option A will probably be found faulty in a rigorous analysis by Prof. Feser.

Rereading the thread, I realized that what Feser and you mean by "whether the PSR holds for our cognitive faculties", which is not "whether the existence and attributes of our cognitive faculties have a rational explanation", as is the standard meaning of the PSR when applied to the universe or anything else, but "whether the mode of operation of our cognitive faculties is rational" or "whether our cognitive faculties work rationally", does not seem to follow from the definition of PSR quoted above: "there is a sufficient reason or adequate necessary objective explanation for the being of whatever is and for all attributes of any being".

Consequences of this definition are, e.g.:

- There is a rational explanation for the rationality of our cognitive faculties.
- There is a rational explanation for the blueness of the sky.

Now, you can argue that a PSR denier is potentially questioning these consecuences, but you clearly cannot argue that he is potentially questioning the blueness of the sky. Why then does the denial of PSR imply the potential questioning of the rationality of our cognitive faculties? Why is it necessary to hold that all of reality is rationally explainable in its structure (being and attributes) in order to be certain that our cognitive faculties are rational in their mode of operation?