Tuesday, June 9, 2020

Skepticism and the Principle of Sufficient Reason now online

Rob Koons' and my article "Skepticism and the Principle of Sufficient Reason", forthcoming in Philosophical Studies, is now online.

16 comments:

Aristion said...

Dr. Pruss,

I think that even if one accepts the PSR and consequently a necessary being, it wouldn’t (by itself) resolve sceptical scenarios due to the fact that every possible world would have an equal probability of being actualized. I think this is a good argument for a *personal* necessary being that is (all else being equal) unlikely to actualize worlds where sceptical scenarios are reasonable possibilities. What do you think?

Alexander R Pruss said...

I agree with the personal necessary being part, though I wouldn't say that every world has an equal probability as I don't know how to make sense of that in light of the infinities involved.

Nagy Zsolt said...

Quote:
"We will claim that the modally robust truth of the Non-Circular PSR for BNFs is a presupposition of all empirical knowledge of the external world, and we further claim that our knowledge of this robust truth cannot (on pain of circularity) be justified empirically. Therefore, the robust truth of this [restricted] PSR must be a priori knowable, if we are to know that we have any empirical knowledge of the external world at all.

Central Claim. If we can know that we have any empirical knowledge of the external world (either in general or with respect to some particular proposition),then we are in a position to know a priori that the PSR for basic natural facts is robustly true.

Why is the PSR in this form a presupposition of empirical knowledge? If this PSR is false, either in the actual world or in ‘‘nearby’’ worlds in any epistemically possible scenario, then we must take seriously the possibility that some natural facts are uncaused. By considerations of symmetry (which we will discuss in Sect.3), if any[/some] natural fact might lack a cause, then any[/all] relevantly similar natural fact might lack a cause. We will argue that any natural fact is relevantly similar to any other. So, if there is some natural fact that might (in nearby worlds) lack a cause, any natural fact might lack a cause."

First, I really don't understand, why the denial and negation of that restricted PSR might lead to all relevantly similar natural facts lacking a cause.
Sure, the denial means that some natural facts might lack a cause. But some things having some specific properties doesn't necessarily entail all relevantly similar things having the same specific property.
Stating so appears to me to be a fallacies and hasty generalisation - as fallacies as deducing from some infinite causal chains being not possible cause of them entailing some contradictions that all infinite causal chains being not possible, even the ones not entailing any contradictions.

Second, well if the denial of the restricted PSR doesn't really lead towards that scepticism, which that paper might wrongly and fallaciously suggest here, then what exactly might lead towards that specific scepticism?
I guess, that the denial of the uniformity of nature would directly lead towards that specific scepticism rather than the denial of that restricted PSR.
If the uniformity of nature doesn't hold, then Aron Wall's pink elephants suddenly appearing out of nowhere and out nothing should be quite expectable and with that also that specific scepticism of ours mentioned in that paper.
Is that previous sentence of mine quite ambiguous? Well not in any given way more ambiguous, then the hasty generalisation presented in that paper here.

James Reilly said...

Zsolt:


The claim is not that if the PSR-BNF is false, then ALL natural facts will lack a cause. The claim is that if even SOME natural facts MIGHT lack a cause (which you admit would be a possibility), then you cannot possibly know whether your own perceptions fall into the "uncaused" category. This lack of knowledge is sufficient to generate perceptual skepticism.

Nagy Zsolt said...

J. Reilly:

First, what exactly is "PSR-BNF"?
I know from that paper above, what RPSR - restricted Principle of Sufficient Reason is supposed to be. But what exactly does "PSR-BNF" stand for and what is that exactly?

Second, well the paper above kinda does argue for "If the RPSR is false or to be denied, then ALL natural facts will lack a cause.":

P1) If this RPSR is false [either in the actual world or in ‘‘nearby’’ worlds in any epistemically possible scenario], then [we must take seriously the possibility that] some natural facts might be uncaused.
P2) [By considerations of symmetry (which we will discuss in Sect.3),] if some[/any] natural fact might lack a cause, then all[/any] relevantly similar natural fact might lack a cause.
C) Therefore, if this RPSR is false, then all[/any] relevantly similar natural facts might lack a cause. (from P1 and P2 by hypothetical syllogism https://en.wikipedia.org/wiki/Hypothetical_syllogism )

So yeah that paper above is all about this exactly.

Third, what if the RPSR is false and I don't know exactly whether my own perception falls into the "uncaused" category? Just because I might not know about my perception being in that "uncaused" category, that doesn't mean that my perception is actually in that "uncaused" category. So I'm sceptical about my lack of knowledge being sufficient to generate perceptual scepticism since my own perception might be caused despite the fact of my lack of knowledge about my perception being caused or uncaused.
Does a cat have to know, that its perception is caused or uncaused to reliably catch mice? I think, that cat doesn’t really have to know, whether its perception is caused or uncaused, in order to reliably catch mice. And similarly I don’t really have to know, whether my own perceptions are caused or uncaused in order to arrive with it at the truth, if there is any truth to be arrived at.
Besides that if the RPSR would be true, then how would I or anybody else know about that to be true. It's like stating, that "Every swan is white." ( https://www.spaceship.com.au/learn/black-swan-event/ )
Every contingent thing has a cause until there is a supposedly contingent thing, which is uncaused and therefore noncontingent such as conserved physical quantities like energy. I guess then there you have it. The necessary thing, which upon all contingent things are depending on. That necessary thing might be energy.

James Reilly said...

Zsolt:

"PSR-BNF" means "Principle of Sufficient Reason for basic natural facts" (the acronym is used in the paper). As for your hypothetical syllogism, there's nothing of that sort in the paper itself, so I'm not sure how it's supposed to support your initial claims (seeing as all you've done here is rephrase your original statement).

Also, you say this: "So I'm skeptical about my lack of knowledge being sufficient to generate perceptual skepticism since my own perception might be caused despite the fact of my lack of knowledge about my perception being caused or uncaused."

But of course, your lack of knowledge is exactly what skepticism is all about! The point of a skeptical argument is just this: that you do not actually KNOW something that you think you know. For you to say "well maybe I don't know it, but that's not sufficient for skepticism" is silly; it's like saying "well sure, I'm an aquatic craniate creature with gills and fins, but that doesn't make me a fish." If you admit that you can't know whether your own perceptions are caused or uncaused, then you've accepted perceptual skepticism, whether you choose to call it that or not.

You also say this: "Besides that if the RPSR would be true, then how would I or anybody else know about that to be true?"

But the entire argument of the paper you're criticizing (which is stated in the abstract, introduction, and other sections) is that we have a priori knowledge of the PSR-BNF. Your analogy of the swan is wrong, because the color of swans that we only have a posteriori knowledge of.

Nagy Zsolt said...

J. Reilly:

Ah, so that's the "PSR-BNF". To be honest with you, it's quite hard to understand everything in that paper. The paper begins with the normal and usual PSR. Then makes a "restriction" about it, so it's called RPSR. Then it's Non-Circular PSR, then it's PSR for BNF's.
And to make it further difficult to follow all of this, that paper is quite consistently inconsistent with the usage of it's acronyms.

Sure, the hypothetical syllogism in itself is not in that paper. Yet the two material conditionals and premises P1 and P2 are in that paper and any hypothetical syllogism is a valid logical inference. So if the paper supposes and proposes P1 "If this [whatever] PSR is false, then some natural facts might be uncaused." and P2 "If some natural fact might lack a cause, then all relevantly similar natural fact might lack a cause.", then it follows logically, that the paper is more or less indirectly proposing C "If this [whatever] PSR is false, then all relevantly similar natural fact might lack a cause.".
This is logic 101.

So according to you now the point of a skeptical argument is, that you do not actually KNOW something, that you think you know? What?

First, previously you stated, that "This lack of knowledge is sufficient to generate perceptual skepticism."
So then do I "not actually KNOW something, that I think I know" or do I "lack a knowledge about something"?
Yes, there is a big difference between these two notions here.
And NO, I'm not saying with "well maybe I don't know it, but that's not sufficient for skepticism", that "well sure, I'm an aquatic craniate creature with gills and fins, but that doesn't make me a fish.".
But I DO say with "well maybe I don't know it, but that's not sufficient for skepticism", that "Well sure, me NOT KNOWING OR LACKING THE KNOWLEDGE OF being an aquatic craniate creature with gills and fins WON'T MAKE ME INTO a fish."
So what exactly is so silly about this notion?

Second, is even someone, anyone capable of actually not knowing something, that one thinks to know?
This really sounds like a contradiction in itself like a "married bachelor" or a "square circle" - you are not knowing something, that you are knowing or you are knowing something, that you are not knowing.
Yeah, I guess, that if I were a fish and not aware of myself to be a fish, then I would be tempted to buy this nonsensical crap of yours.
Since I'm not a fish, at least not that I'm aware of that to be, I'm not buying this nonsense and crap of yours.

Sure, the particular and specific color of swans might have been empirically obtained and therefore being an a posteriori knowledge of ours.
But the state "Every/ALL Swans are white." is a hasty generalisation - postulation just like the [whatever] PSR. This a priori knowledge about ALL swans being white has been by the way empirically falsified.
Did you read that article in that provided link? I advise you to do so. It's quite interesting.

Quote from that paper (not the previously mentioned article):
"Non-circular PSR for basic natural facts If the xx’s are basic natural facts, then there is a y that is not one of the xx’s or part of any of the xx’s, and y explains the xx’s."

Yet there still might be a "Not-White/Black Swan'' out there - being one of the xx's or part of any of the xx's explaining the xx's. Maybe something like apparently noncontingent and unchanging physical constantes like for example energy?
Yeah, I think, I'm aware of those. How about you? Are you aware of those or do you actually not know something, that you think you know?
I guess, it's the latter.

Alexander R Pruss said...

To be honest, while scepticism is usually defined as a thesis about *knowledge*, I don't really think knowledge matters much if at all, and so scepticism as normally defined does not seem to me to be a very interesting thesis.

What is more interesting are questions like this; If we accept a given view (say, the denial of the PSR), do we have significant reason to accept the deliverances of our senses? If not, then we have something stronger and more interesting than scepticism.

James Reilly said...

I think whether we choose to phrase the issue of terms of knowledge, or just reasonable trust in our senses, the point still comes out in basically the same way: once you acknowledge that you have no idea whether your perceptions are caused or uncaused, you lose rational basis for trusting them. To insist (as our above interlocuter is doing) on a practical distinction here, as if one could concede the falsity of the PSR-BNF while continuing to trust their senses, seems misguided.

Alexander R Pruss said...

I don't know. Rationality in these weird cases is tricky. Suppose you have very good evidence that you don't exist--you've read Unger's argument, and can't see any way of denying any premise. But you also can't get yourself to deny your own existence. Are you irrational in saying that you exist while holding that the argument is sound? You wouldn't be less irrational if you held that the argument was sound AND that you don't exist--for to hold that you don't exist is close to the height of irrationality, and seems more irrational than holding that a sound argument has a false conclusion.

Nagy Zsolt said...

J. Reilly:

First, yes, if one acknowledges, that there is no idea or a "lack of knowledge" whether one's perceptions have or haven't been caused, then there might be no warrant in trusting in those received perceptions. Yet again is that warrant in any given way necessary in order to come to the bottom of any truth? If a cat might not need a warrant of its perceptions being reliable or an actual acknowledgement about its perceptions being caused in order to reliably catch mice, then I also might not need a warrant of my perceptions being reliable or an actual acknowledgement about my perceptions being caused in order to find the truth.

Nagy Zsolt said...

J. Reilly:

Second, I do think, that the restricted PSR-BNF is actually false and that I can trust my senses since I don't see any connections in between those two things or to say, that they would exclude each other.
If the restricted PSR-BNF constitutes nothing but, that "If the xx’s are basic natural facts, then there is a y that is not one of the xx’s or part of any of the xx’s, and y explains the xx’s.", then the denial and the negation of that restricted PSR-BNF means nothing but, that
Not-"If the xx’s are basic natural facts, then there is a y that is not one of the xx’s or part of any of the xx’s, and y explains the xx’s"
≡ The xx’s are basic natural facts and Not-(there is a y that is not one of the xx’s or part of any of the xx’s, and y explains the xx’s)
≡ The xx’s are basic natural facts and there is no y, that is not one of the xx’s or part of any of the xx’s, and y explains the xx’s
≡ The xx’s are basic natural facts and there is a y', that is one of the xx’s or part of any of the xx’s, and y' explains the xx’s.
Sure, we might include, that such a y' to be uncaused or to say "brute fact" of reality. Does that now mean, that such a y' pops into existence suddenly from nothing out of no reason? No, that's not necessarily the case here.
That might happen if and only if the uniformity of nature would be false or wouldn't always hold and that sudden coming into existence out of nothing and from nowhere for no reason would only be considerable here if and only if the uniformity of nature would be denied here simultaneously alongside that "restricted PSR-BNF".
But I don't do that. I'm rather on the opposite site here: I am a proponent and a proclaimer of the uniformity of nature and yes, at the same time I'm denying that restricted PSR-BNF, which means, that I'm claiming, that there is such a y', that is one of the xx's/a basic natural fact or a part of any of the xx's, and y' explains the xx's and further I'm claiming, that such a y' is a brute, basic natural fact of reality, which might have never come into existence since, it might have been always here/there existing i.e. physical constants such as energy.
As far as we KNOW, neither energy can be produced out of nothing nor energy can be destroyed into nothing. Energy comes always from somewhere, then forming and shaping into something and then going somewhere else and therefore energy might be considerable as to have been always somewhere - not coming suddenly from nothing.
And what does all of this has to do with perceptions or with the reliability of perceptions? Yes, exactly. This and the denial and negation of that restricted PSR-BNF have nothing to do with perceptions or with the reliability of perceptions. At least there is no direct and trivial link between those two things as Koons and Pruss make that out to be in that paper. That direct and trivial link, as Koons and Pruss are portraying in that paper of theirs, is a "Hirngespinst" - a pipe dream.
I don't get that connection. For me the thing with the unreliability of the perceptions given the denial and negation of that restricted PSR-BNF might as well be a "red herring" - nothing of a proper meaning to the discussion and debate and nothing more than a distraction.
Either that or I'm "misguided". If I'm really "misguided", then don't just simply state and claim that to be the case, but then please also give a proper explanation, James, why exactly is that the case, or please at least clear and explain things up in such a way, so that I can understand it and then I'm not "misguided" any more.
Thank you.

Nagy Zsolt said...

A. R. Pruss:

I do agree with you, that "knowledge" doesn't really matter here. Maybe it does matter a tiny bit, but not much.
Do I know, whether or not, that Santa Claus exists? No, I do not really know.
Do I assume, whether or not, that Santa Claus exists? It would be ignorant to say, that given the lack of empirical evidence for the existence of Santa Claus, therefore Santa Claus doesn't exist (fallacy of ignorance). But it is not unwarranted to say, that probably Santa Claus doesn't exist, since the non-existence of Santa Claus explains quite well, why there is no empirical evidence of the existence of him. So the assumption of the non-existence of Santa Claus is not unwarranted or to say (cause of double negation), that the assumption of the non-existence of Santa Claus is warranted because of the lack of the empirical evidence of his existence and cause of the thesis of the non-existence of Santa Claus explaining quite well such a lack of empirical evidence of the existence of his.

Now, where was I? Ah, yes:
Do you or anybody "know", that the restricted PSR-BNF holds or is correct?
No, nobody knows, that to be the case, just like nobody really “know” the statement and claim "Every/All Swans are white." to be the case, since that would require checking and "know" about each and all existing swans to be white or each and all basic natural facts xx' not explaining any other basic natural facts xx.
On the other hand one might assume the statement and claim "Every/All Swans are white." to be true with a more or less proper warrant such as an inductive argument from few or quite a lot of (but not all) examples of swans being white(, which is by the way just a nice way of putting it to make a maybe fallacious hasty generalization from a few or quite a lot but not all examples).
This is also really the case here for that restricted PSR-BNF: There is no real "knowledge" about that restricted PSR-BNF to be true and that can only be assumed to be true here with a more or less proper warrant.
I do think, that your warrant for that restricted PSR-BNF to be the case is improper and I hope, that finally I have been capable of articulating my warrant against it in my response for J. Reilly above. I really don’t understand, how that scepticism follows more or less promptly and directly from the denial and negation of that restricted PSR-BNF. How exactly?
Sure, if one might want to simultaneously deny the uniformity of nature, then I can see that entailment of scepticism for the reliability of our perceptions. But without that denial and negation of the uniformity of nature I don’t really see that scepticism to be necessary.

Unknown said...

Uhm...in the first sentence of your paper you admit that you are committing the Argument From Consequences fallacy.

Alexander R Pruss said...

Or else it's modus tollens. :-)

Unknown said...

You might be able to classify it as modus tollens if your first sentence was "The Principle of Sufficient Reason must be justified dialectically: by showing the impossibility of denying it." But what you said was "The Principle of Sufficient Reason must be justified dialectically: by showing the disastrous consequences of denying it." which is absolutely an argument from consequences. :-)