His argument is that the parts of the judgement are not even necessarily linked if the PSR is false, which is worse than the Cartesian Demon situation, and that one cannot form a syllogistic argument without the PSR. This is because to do so would be to believe that your premises and conclusion follow a sort of entailment relation, which if the PSR is false would not necessarily be the case. And yet one does rationally make an argument against the PSR, and to do so would perhaps lead to an infinite regress of these syllogisms (for she would also have to argue that her syllogism avoids the conclusion being an unrelated brute fact, and then that conclusion, and so forth). To even come to the conclusion of Agnosticism about the PSR would be to fall into the same error, for one would have to form a syllogism with regards to your reasons for not accepting it, which is again, self refentially incoherent.

At the very least, you are able to attack a weak sort of skepticism by a retorsion argument that a denial of the PSR is self referentially incoherent. However, I would argue that perhaps even the link between object and belief is compromised if the PSR is false, which makes it worse than the Cartesian Demon situation. So this would not merely be believing things for the wrong reasons, but the reasons themselves not being necessarily linked with the other parts of your mind. Plus how can one appeal to any objective tendency, since to deny that the PSR holds would make objective tendencies not of necessity true, and so one can't appeal to anything external maybe making a demon's thoughts and actions disconnected. This makes all of reality a big giant kablooey, not the sort of thing that one can rationally affirm or deny. Yet one can rationally access her reasons for denying the PSR. Hence, a denial leads to a retorsion argument. One can press another argument like the ones Feser gives, that since say knows his reasoning when denying the PSR to an interlocutor, that his mouth is moving at a connected manner with his speech, and that his thoughts are connected to his speech and that a link obviously exists between the group (at least within the mind), one is compelled to accept the PSR is true at least with regards to intellectual judgement. However, when one does this, you can press them, with two options A. Is their some fact assuring that the PSR only governs the mind, hence making this fact outside of mental judgement  or B. Is it merely a brute fact. Either options amounts to the conclusion that the PSR is not necessarily true with regards to mind (since how can one assure at that point the absurdities will not creep in yet again). One can do this with any layer of reality that is questioned to not be governed by the PSR.  

Another argument one can give is that since our experiences as a unified whole are key to our status as rational animals (and can be arrived at via introspection), Koon's argument for the PSR due to it's denial being self referentially incoherent is a good argument, and perhaps available just from this alone. Even the link between thinking and concluding that you are might implicitly assume a link. Obviously the basis for Descartes argument would still hold true, and yet in order to remotely rationally justify this conclusion, the PSR would have to be true.

Lastly, I would say that one doesn't have to assume  an infallibility to your epistemology, and that she can simply say this is as obvious a fact as say the external world. One concludes when lifting his arm that their is an obvious link between the will and the movement, and since a denial of the PSR would make this not necessarily so, why would one want to prefer an option that is in opposition to this? I am a lot more sure of these certain facts than I am of any skeptical situation. One could rest a whole lot of assurance on this. But a collolary of this is that the PoC is true. Therefore, one ought to prefer the PoC being an objective fact about reality.

Last edited by Camoden (6/18/2017 11:00 am)

UGADawg wrote:

His argument is that the parts of the judgement are not even necessarily linked if the PSR is false, which is worse than the Cartesian Demon situation, and that one cannot form a syllogistic argument without the PSR. This is because to do so would be to believe that your premises and conclusion follow a sort of entailment relation, which if the PSR is false would not necessarily be the case.

This is the case regardless of whether PSR is true or not though. Even if PSR is true, there remain skeptical scenarios that cannot in principle be eliminated (e.g. brain in vat, Cartesian demon, etc.). Yet we don't take that possibility to commit us to skepticism. But if that's the case, neither should we take PSR being false to commit us to skepticism, as it hinges on the mere potentiality that our beliefs are false, just as the usual skeptical scenarios do.

I would argue that it is more than just that. I don't think the skeptical situations even commit us to something that absurd. It is once you grant this, you can't even access the probabilities for any situation, akin to Pruss's argument from inferences to the Best Explanation. But I would argue the weight of the argument isn't even in the mere skepticism of these arguments, but that they are self referentially incoherent. Remember Feser admits one could grant the skeptic situation, but any theory which denies explicitly what it affirms impliclty is absurd. Since the skeptic does this, his position is absurd. That is the weight of the argument. Still, I think even in the demon situation you can still affirm certain facts in a rational manner, which is not necessarily true under the no PSR world. The link between the reason and the affirmation, and the demons deception is a link that still allows for rational justification, one can still claim that he exists, even if the demon is deceiving him. While he can do the same thing in the other situations, it is of an entirely different sort. Still, the crux of the argument is that it is almost a sort of Moorean Fact, one that should easily be preferred, even if not infallibly so. Easily something one would trust a great deal more than any skeptical situation.

Last edited by Camoden (6/18/2017 1:37 pm)

Thanks for the welcome. Also sorry for the long delay in replies, I got busy and forgot about the topic.

Here's another way of thinking about it. Consider Michael Huemer's phenomenal conservatism, which says we're justified in believing something if it appears to us to be true and there are no defeaters for the appearance (i.e. no reasons to think it is false). He defines an appearance as a mental state in which something seems to be the case to us. There are different types of appearances, e.g. a sensory appearance would be an experience in which it seems to be the case that there is (say) a computer in front of me that I am typing this post on. That appearance would be sufficient to justify my belief that there actually is a computer in the absence of any reason to think there isn't one. Huemer further argues all rational beliefs are ultimately dependent on appearances, e.g. if my belief that P is rational, this is caused by and based on the fact that P appears to be true, or perhaps that Q appears to be true and it appears Q supports P, or perhaps that R appears to be true and R appears to support Q which appears to support P, etc.

So, what about the retorsion argument? It seems to me if Huemer is right the retorsion argument has no force. It definitely appears to be the case that our beliefs have explanations (Feser indeed grants this in his exposition in Scholastic Metaphysics). So that belief (i.e. our beliefs or cognitions have explanations) is justified if there are no defeaters for the appearance that our beliefs have explanations. So how would rejecting PSR be a defeater for that appearance? All rejecting PSR means is that it's possible our beliefs are without explanations. It does not by any means entail that they do not have explanations. Yet the possibility that an appearance is false is not sufficient to undermine the appearance. In the above example, the possibility that P is false isn't sufficient to defeat the justification based on the appearance that P is true. Or the possibility Q is false and the possibility Q doesn't support P isn't sufficient to show either of beliefs aren't justified in virtue of the fact they appear true (and that therefore the belief in P is unjustified). And so forth.
 

Last edited by UGADawg (7/18/2017 7:40 pm)

PS I probably cannot reply for a few days.

Good discussion.

I know the OP is focusing on one of Feser's main arguments for the PSR as a self contained argument, but I wonder what Pruss' argument from objective probabilities would play? In order to provide a defeater to PC epistemology, the argument cannot appeal simply to the broad possibility, but what if, as Pruss argues, objective probabilities are undermined by denying the PSR? What that mean that the whole issue of justifying a defeater is itself defeated? For we do not have the foundation from which to demand significant probability of a defeater, given a rejection of PSR.

Also, and this isn't a specificly worked out thought, but Feser argues that metaphysics is more fundamental than epistemology, maybe any coherent epistemology would have to assume PSR? Afterall, isn't the point of the argument to ground rational enquiry, and it is based on rational argumentation that tye PC theory of epistemology must be justified. Would assuming that epistemology also be to assume the PSR? Im not sure. Mainly because of the entangled roles epistemology and ontology have in Feser's argument.