It is not all that infrequent here at TSZ that some opponent of theism or ID makes a statement that makes me scratch my head and wonder how it is possible that they could make such a statement. This OP explores a recent example.
Cartesian scepticism, more impressed with Descartes’ argument for scepticism than his own reply, holds that we do not have any knowledge of any empirical proposition about anything beyond the contents of our own minds. The reason, roughly put, is that there is a legitimate doubt about all such propositions because there is no way to justifiably deny that our senses are being stimulated by some cause (an evil spirit, for example) which is radically different from the objects which we normally think affect our senses.
– A Companion to Epistemology, p. 457
Imagine my surprise when I found keiths (a self-identified “Cartesian Skeptic”) appealing to the senses.
The big difference between moral and factual judgments is that the former funnel down to a single “point of failure” — the conscience — while the latter do not. That doesn’t mean that the latter can’t be wrong, of course, but it does raise the bar for error.
…
Of course, even if you do all the things I listed in order to confirm that your monitor is there, you still don’t know (without the asterisk) that it’s there. The Cartesian demon might be fooling you, or you might be an envatted brain.
But at least your judgment depends on multiple sensory channels rather than on a single faculty like the conscience.
Is keiths assuming there’s only one demon and that demon can only stimulate one of his senses at a time?
Of course, noting the inconsistency of keiths, I felt compelled to speak up.
…what makes you think that multiple sensory channels is better than one, or better than a conscience?
While we still await a response from keiths (who always defends his claims) a good buddy of keiths, Richardthughes, took up the challenge.
consilience (The same reason science is better than the bible)
Wikipedia article on Consilience
The principle is based on the unity of knowledge; measuring the same result by several different methods should lead to the same answer.
[Patrick, if you need help with those links let me know. Don’t just claim that they do not exist.]
For a “Cartesian Skeptic”, how is it that multiple sensory channels is better than “a single faculty like the conscience”?
How does “consilience” come to the rescue of the Cartesian Skeptic? Consilience is based upon the unity of knowledge, and it would seem to me that there must be something that bring about this unity. How is the “consilience” of the senses brought about? Perhaps Richardthughes is just confused. Maybe keiths will come to the rescue of his wingman.
I say that in reality we are not in any particular Cartesian scenario and that you have no evidence to the contrary.
Should we toss a coin to see which of us is right?
Or do you think that the likelihood of us being in a any particular Cartesian scenario is better than 50/50. Perhaps the cartesian demon wields a loaded coin.
Assume that all Cartesian scenarios are equally likely.
Assume that all Cartesian scenarios are equally likely to be true.
Assume that all Cartesian scenarios are equally likely to be false.
I don’t think that’s so. I think that there are some cases in which that’s true, but it’s not a general epistemic principle.
I think it’s correct that knowledge involves justification, and also that in empirical knowledge, justification sometimes involves probabilities. But even empirical knowledge doesn’t have to involve probabilities, just because it doesn’t consist of claims that are necessarily and universally true.
My justification for believing that my car is in good working order, even though I haven’t driven it in a few days, consists of my reasons for asserting that it’s in good working order: it was in good working order when I drove it last, I drove it recently, it’s unlikely that anything bad has happened to it since I last saw it, etc. It is likely that my car is in good working order, but that is a consequence of my having good reasons for believing that it is. The estimation of likelihood isn’t itself a reason.
On the other hand, in statistical reasoning, the estimation of probabilities is essential to the justification of the claim being made.
Still, the claim that the senses are veridical doesn’t have to be grounded in estimation of probabilities in order to be known. For that claim is not itself a claim of empirical knowledge — although empirical knowledge can, to a substantial degree, vindicate that claim. The claim that the senses are veridical (or that they aren’t) is a philosophical claim that has to be assessed on the basis of careful reasoning.
But do you want to say that all knowledge that is not deductively valid must be knowledge of probabilities, and effectively assimilate all empirical knowledge to statistical reasoning?
Though, to return to a point I’ve made several times in the course of these conversations, I think of scientific knowledge as practical knowledge made more systematic and rigorous in order to yield more reliable practical results. So I think that critical realism, according to which the proper functioning of our perceptual capacities is to detect and classify features of our environments for the sake of more successful action, is all the epistemological ‘foundation’ that science needs. And that critical realism is far more intuitively plausible than any skeptical argument.
I’ve pointed out before that this claim is likely to be false, and if we therefore agree with keiths, then it follows that we cannot know that it is true And if we cannot know that it is true, then we have no reason to believe that it is true.
Of course this entire line of reasoning is suspect. It turns epistemology on its head. It conflates knowledge with justification and assumes without argument that knowledge can only exist in the presence of inductive logic, a claim that cannot be demonstrated by inductive logic.
If we apply the logic of keiths, we cannot possibly know that his claims are true. If we cannot know that his claims are true, we have no reason to believe his claims are true. But, given his logic, that we cannot know that his claims are true is a basis for disbelief.
What I happen to know about this alleged principle is that it’s question-begging. I deny it, it’s completely inconsistent with ordinary language and common sense, and I have been waiting to hear a single shred of support for it through about seven long threads now. Of course, I never will hear anything. Here’s why.
As Mung says, if somebody knows this principle, on that person’s view it will have to be likely. But we’ve seen no inductive (or any other sort of) evidence adduced on its behalf, because it’s clearly not the sort of claim that is subject to probabilistic support. That is, if it’s true, not only could nobody ever know it, but nobody could be justified in believing it, Indeed nobody could ever have the slightest bit of evidence for suggesting it. I’ll go further: if it were known to be true, it would have to be false.
I suppose one could claim that the “legitimately” implies some sort of judgment of an objective value regarding what OUGHT and OUGHT NOT to ever be claimed. That would be even more ridiculous considering its source here (Evan).
The very contemplation of this absurd alleged epistemic principle is a waste of life–except for seeing its absurdity, which I suppose might be worthwhile ONCE. But not 100 times!
For Christ’s sake, Evan. Give it up. I know pixels are cheap, but there’s got to be a limit to blowing them on gibberish in this weird, insistent manner.
I think that we now have a logical explanation for why Christ died.
On His way to India?
keiths:
walto:
Good. Then you can show us why Yolanda’s statements make perfect sense in her exchange with Xavier:
I’m looking forward to your explanation.
Not if you accept The Gospel According to Biff!
Lamb: The Gospel According to Biff, Christ’s Childhood Pal
They absolutely do make perfect sense, Tomiqua. People generally don’t have any clue of the likelihood of the things they know. It’s a stupid question. Who the hell thinks this is true:
Tomiqua either knows the likelihood that her name is really Tomiqua or doesn’t know her own name.
It’s a completely moronic suggestion (unsurprisingly).
ETA: As you were “looking forward to my explanation,” Tomiqua, I hope you’ll try to understand it this time. I’m sick of having to give you these repeated, remedial lessons. I really don’t think you’re trying.
They do make perfect sense, but that perfect sense which they do make contradicts your claims.
Yolanda: I have no idea whatsoever.
Yet you claim to know.
Not sure Biff was still with Him after He was cut down and restored to health by Joseph.
There were so many contradictions in that book, but I had no logical reason to reject any of them.
Hmm.
I know Boyle’s law. And I know that it is false, though a good approximation.
Jesus, walto. If she didn’t think it was likely that her name was ‘Tomiqua’, then she wouldn’t claim to know that her name was ‘Tomiqua’.
Neil,
That’s an equivocation on ‘know’. We’re not talking about ‘I know’ in the sense of ‘I am acquainted with’.
“I know that my senses are veridical” means “I know that the proposition ‘my senses are veridical’ is true.”
KN,
You’re making my point for me — see the bolded word ‘unlikely’ above. You can justifiably claim to know that your car is in good working order only because it is unlikely that anything bad has happened to it since you last drove it.
Suppose you left it three days ago in the worst part of New York City, or on a battlefield in Syria. In that case it is no longer unlikely that something bad has happened to it — quite the opposite. The claim “I know my car is in good working order” is no longer legitimate.
A couple more examples, just to drive the point home:
I leave a $50 bill in the middle of my kitchen table, under a small paperweight. Two hours from now, I tell you that there is a $50 bill on my kitchen table. You ask me how I know that, and I tell you that I left one there, that I haven’t moved it since, that it couldn’t be blown off the table because it was under a paperweight, that no one else has a key to my house, that my 22-year-old cat is no longer capable of jumping up on the table and knocking the bill off, that there hasn’t been an earthquake, etc.
I’m not certain that the $50 bill is still there — someone could have broken into my house and taken it, among other possibilities — but the likelihood is low enough that I’m justified in claiming to know that the bill is there.
Now suppose instead that I leave the $50 bill on the arm of a bench in the middle of Grand Central Station at 10 AM on a normal weekday. It’s now extremely unlikely that the bill is still there after two hours, so if I claim to know that the bill is still there without having verified it somehow, then you can dismiss my knowledge claim. It’s illegitimate.
Likelihoods are crucial.
KN,
There’s a reason I use the word ‘likelihood’ in place of ‘probability’. You’re skating close to walto’s persistent error, the one I warned against yesterday:
It is pretty much the ordinary usage “know”.
There are multiple usages, Neil.
“I know X” in the sense of “I am acquainted with X” is not the same as “I know X” in the sense of “I know X to be true”.
“I know that my perceptions are veridical” is an instance of the latter, not the former.
ETA: In Spanish, there are different words for those two senses of “to know”. The verb for the former is “conocer”, and for the latter it’s “saber”. When tackling Spanish, native English speakers have to learn to make that distinction.
It’s similar for the French “connaître” and “savoir” and for the German “kennen” and “wissen”. German throws in another wrinkle with “können”, as in “Ich kann nicht Italienisch” — literally, “I can not Italian” — for “I can’t speak Italian”.
I don’t know about “to know” in Italian or other languages.
KN,
You’re taking all possible worlds as ontologically real, but that isn’t necessary. You made the same mistake earlier in the thread in characterizing my view as metaphysically extravagant:
Nothing about my Cartesian skepticism requires us to grant ontological reality to multiple possible worlds or to worry about the “adjacency” of possible worlds to the real world.
Remember, we’re talking about epistemic likelihoods. The uncertainty is with respect to this world, the real world.
Again:
All of this concerns the real world. In the real world, it is epistemically possible that we are brains-in-vats. It is also epistemically possible that we are not brains-in-vats. In ontological terms, one or the other must obtain. It is not ontologically possible that we both are, and aren’t, brains-in-vats (assuming BIV-hood is well-defined).
To speak of possible worlds in this context is merely to acknowledge the multiple epistemic possibilities. It doesn’t commit one to asserting the ontological reality of those multiple possibilities.
True but native speakers still blur the distinction. And the old distinction between être and se trouver is fading.
Oops ETA right verb
How do you know this, epistemically? 😉
That, is completely and obviously false, Kibner. Unless “thinking it’s likely” just means thinks its true. That, for those who might miss it, is the equivocation you’re playing on here.
Oh Kibble. You got anything else or are you just going to see how many fallacies you can shove into one thread?
BTW, Adding the “Jesus” at the front of your post doesn’t help it a single iota. Ain’t no Jesus any more than there are virtual cows.
There are some contexts in which it makes sense to talk about likelihoods of empirical or matter-of-factual propositions. But it doesn’t make sense in all contexts, and it surely won’t do as an analysis of the concepts of either truth or justification.
In any event, a correct analysis of “the senses are veridical” shows, a la Peirce, that it is not itself an empirical proposition but a constitutive principle of all empirical inquiry — even though it can be vindicated by empirical inquiry (e.g. cognitive science of perception).
keiths:
walto:
The following are all nonsensical, walto:
The knowledge claims clash with the likelihood assessments, rendering the statements nonsensical.
KN,
Including this one. It’s a matter of fact that we either are, or aren’t, brains-in-vats, or being Carteased in some other way.
The problem is that we can’t justifiably assign either a high or a low likelihood to that possibility.
We can’t know that our senses are veridical, and so any knowledge claims based on their veridicality are illegitimate.
Bechtold doesn’t get this, KN and it’s clear he’s never going to. We’re wasting our (and everybody else’s) time…..
From the absolute point of view or view from nowhere, it is a matter of fact whether or not we are being ‘Carteased’. That is to say, from God’s perspective.
The more we interact, the more it seems to me that your Cartesian skepticism is motivated by insisting on a theocentric conception of what knowledge is, then noticing that no human being can ever satisfy it. (There’s a similar motivation to the ancient Greek Skeptics. You should read “Outline of Pyrrhonism” by Sextus Empiricus.)
The contrary view that I endorse is grounded in the shift from theocentric to anthropocentric conceptions of knowledge begun with Hume, Kant, and Reid and then gets developed into a serious philosophical program with Peirce and subsequent pragmatist epistemologists (e.g. Michael Williams, Susan Haack, Jay Rosenberg).
Pragmatism is anti-skeptical, not by virtue of attempting to refute skepticism, but by virtue of starting off from a different conception of what knowledge is — one on which skeptical worries simply cannot get off the ground. As Walto notes (though he’s not a pragmatist), the skeptic’s modus ponens can be countered with a pragmatist’s modus tollens.
When the skeptic says, “you don’t know that you’re typing on a computer because you don’t know that you’re not a brain in a vat,” the pragmatist can simply flip it around, “I do know that I’m not a brain in a vat because I do know that I’m typing on a computer.” (There’s even a song about this that Walto will appreciate.)
The slightly deeper points to consider here:
(1) as inference rules, modus ponens and modus tollens appear to be contrary. But in fact they both say the exact same thing: that one ought not accept all of p–>q, p, and ~q. The inference rules only seem different because of how the information is organized.
(2) neither inference rule tells us what we should do. It could be that we have stronger reasons for accepting both p and ~q than we have for accepting the conditional, so it should be the conditional that gets rejected.
Yep. I’m done.
I know my truck was running the last time it was running. And I know my truck will be running the next time it is running. And I have no reason to believe my truck will not run the next time I start it. Why should I concern myself with likelihoods when I have no reason to doubt?
Mung,
You could reduce the uncertainty by going out at frequent intervals in the night, fire up the engine for a second or two, and then you could sleep more easily…
Oh wait!
KN,
I’ve responded on the new thread.
But are you not going to respond to my simple questions?
We might find your posts on certainty a bit more interesting if you could explain the point. What are the consequences of being a Keithsian Skeptic?
What’s the point?
ETA: I see you say “it works”. In what way?
Alan,
You ask that question again and again, ignoring my answers, including here.
The fact that you ignore my answers despite claiming to be interested in dialogue is one reason I’m limiting my interactions with you. Another is that you and Mung are completely lost on this topic. Look at these comments of Mung’s or your comments here, here, and here. It would take a lot of effort — more than I’m willing to invest — to overcome your and Mung’s inability to understand what’s actually being discussed here.
Though I’m not responding to your comments, I am reading them. If either of you manages to catch up and say something worthwhile, I’ll address it.
I’m not willing to spoon-feed either of you, but others are welcome to do so if they wish.
keiths,
Your link does not take me to an answer to my question. What consequences follow from your realisations?
If you are disappointed with the general reception to your ideas on certainty, why not try a more specialist venue (philosophy forum perhaps?)
I’m with you there. I’m quite in the dark as to how simply entertaining the ideas that “the veridicality of our senses is an assumption we’re making, not something that can actually be demonstrated” and “the real world might therefore be nothing like what we take it to be” is supposed to make a difference to our practical conduct.
(Notice that, by contrast, for the ancient Greek Skeptics, there were real practical consequences of their skepticism — namely, a disciplined refusal to inquire into the causes of things and a corresponding liberation from anxiety and desire.)
That would be highly entertaining.
Alan,
I’m not disappointed. Two philosophy PhDs have been trying for months to find an effective argument against my Cartesian skepticism. That’s the kind of critical scrutiny I want for my ideas.
That fact that you and Mung can’t keep up is irrelevant.
But as a Cartesian Skeptic you can’t be sure of that. You may be disappointed, there may be effective arguments, you may not want scrutiny.
newton,
Only the second of the three, because that involves the external world, about which we can’t claim knowledge.
All I know is that in this world — whether it’s virtual or real — the two philosophy PhDs have failed to present effective arguments. One of them is reading up on the topic, though, so let’s see what tries next.
I have not been commenting at TSZ lately..
I have been watching a lot of Olympics.
One thing about the Olympics: as far as I can tell, none of the athletes gets to score their own performance.
…
I’m officially amused.
I seem to recall starting an earlier thread, Facts as human artifacts. And I seem to recall you expressing the view that facts are metaphysical entities. My view was that if there are metaphysical facts, then we have no access to them.
Now, in your skepticism, you might be reaching a similar conclusion.
For me, knowledge has to do with how we manage our lives. If I say “the dog chased the cat up a tree”, it doesn’t actually matter whether dogs, cats and trees are things in the external world. What matters, is that they are part of how our experience is structured (or of how we structure our experience).
I seem to recall saying somewhere (I’m not sure which thread), that there’s no such thing as “the way the world is”, or, if there is such a thing, it is not accessible to us. And, I seem to recall that you disagreed.
So, in some ways, we agree. You get to your view via Cartesian skepticism. I get to my view via my attempt to understand the principles of cognition.
But here’s the big difference. You see all of this a reason for skepticism. I see it as a reason for optimism. You conclude that we cannot trust perception. I conclude that, generally speaking, we can trust perception.
Why the difference. Your pessimism is because you think perception should tell us the way the world is. That’s your theocentrism at work.
My optimism is because I think perception should be an effective guide to living our lives. That’s my pragmatism at work.
It would be interesting if they did, if the gold medal went to the second highest score.
In terms of arguing against genuine Cartesian skepticism — which is not quite keiths’s position, since Cartesian skepticism makes no use of subjective estimates of likelihood — there is no “refutation”. All that is required is understanding that it is a position that cannot be taken seriously. In my estimation it is Peirce who established this most firmly and decisively, first in his “Some Questions Regarding Four Incapacities” (1868) and then in “The Fixation of Belief” (1877).
In particular, I draw your attention to the following:
—————————————————————————-
To satisfy our doubts, therefore, it is necessary that a method should be found by which our beliefs may be determined by nothing human, but by some external permanency — by something upon which our thinking has no effect. Some mystics imagine that they have such a method in a private inspiration from on high. But that is only a form of the method of tenacity, in which the conception of truth as something public is not yet developed. Our external permanency would not be external, in our sense, if it was restricted in its influence to one individual. It must be something which affects, or might affect, every man. And, though these affections are necessarily as various as are individual conditions, yet the method must be such that the ultimate conclusion of every man shall be the same. Such is the method of science. Its fundamental hypothesis, restated in more familiar language, is this: There are Real things, whose characters are entirely independent of our opinions about them; those Reals affect our senses according to regular laws, and, though our sensations are as different as are our relations to the objects, yet, by taking advantage of the laws of perception, we can ascertain by reasoning how things really and truly are; and any man, if he have sufficient experience and he reason enough about it, will be led to the one True conclusion. The new conception here involved is that of Reality. It may be asked how I know that there are any Reals. If this hypothesis is the sole support of my method of inquiry, my method of inquiry must not be used to support my hypothesis. The reply is this: 1. If investigation cannot be regarded as proving that there are Real things, it at least does not lead to a contrary conclusion; but the method and the conception on which it is based remain ever in harmony. No doubts of the method, therefore, necessarily arise from its practice, as is the case with all the others. 2. The feeling which gives rise to any method of fixing belief is a dissatisfaction at two repugnant propositions. But here already is a vague concession that there is some one thing which a proposition should represent. Nobody, therefore, can really doubt that there are Reals, for, if he did, doubt would not be a source of dissatisfaction. The hypothesis, therefore, is one which every mind admits. So that the social impulse does not cause men to doubt it. 3. Everybody uses the scientific method about a great many things, and only ceases to use it when he does not know how to apply it. 4. Experience of the method has not led us to doubt it, but, on the contrary, scientific investigation has had the most wonderful triumphs in the way of settling opinion. These afford the explanation of my not doubting the method or the hypothesis which it supposes; and not having any doubt, nor believing that anybody else whom I could influence has, it would be the merest babble for me to say more about it. If there be anybody with a living doubt upon the subject, let him consider it.
—————————————————————————–
To reject the hypothesis that there are Reals that affect the mind in lawful ways is to reject all hope of dialectically stable inquiry. One certainly may do so — as indeed the ancient Greek Skeptics did — but one cannot seriously inquire without committing oneself to the veridicality of the senses. And one cannot commit and doubt at the same time, for they are contrary attitudes.
One can doubt some particular claim, or question which of two (more) incompatible claims should be accepted, but only by also at the same time taking for granted a whole background of commitments that give sense, purpose, and value to that particular inquiry.
Whereas Neil seems to think that pragmatism is somehow distinct from realism, I take the Peircean view (also that of Dewey, Sellars, and others) that pragmatism in method yields realism in content, and that scientific methods are epistemically privileged in generating stable and reliable access to reality. None of the arguments for “idealism” — whether Berkeleyian or Kantian — are philosophically acceptable — Berkeley (and Descartes) being effectively demolished by Kant, and Kant by Hegel (esp. Hegel as brought up-to-date and shorn of metaphysical exuberance in Peirce, Dewey, and Sellars). Likewise all the arguments for skepticism have their own fatal dialectical instabilities, as Hegel showed and as Hegelians have been showing us ever since. (In particular I recommend Westphal’s excellent work on skepticism.)
Indeed.
A couple of your remarks have caused me to reflect. I like the concept that we are brains in vats – encased in bone and bathed in cerebrospinal fluid. Our only contact with the external world is via our sensorimotor system, imperfect as it is. We can however work with the feedback we gain, cows smell, rocks hurt our foot when we kick them, to build an improving model of the external world, especially as we can store and share information and enhance our senses with telescopes, microscopes and so on.
And I like the concept that there isn’t an inner world and an external world. We are a bit of the external world, not separate from it. Our thoughts are neural activity in nervous tissue, we are particles and energy. It’s one world.
Sorry, I was out looking for a VR headset that delivers veridical information.
What keiths meant to say was that he writes and writes ad writes, till he’s tired of it, and simply cannot understand how we can know that what we have read by him is veridical. Maybe that’s what the good faith rule is there for.
Where did the idea of a virtual world come from, if not the real world?
Why do you claim to have knowledge of virtual worlds, unless they are merely internal to your mind and have no correspondence to the real world?
You see Yolanda, I can keep up, the problem seems to be in getting you to admit you are wrong with an argument which you are willing to admit shows you are wrong. And it has not been for lack of trying.
I said keiths was not a Cartesian Skeptic. He never admitted I was right.
You are the one who has been trying to convince me that I am not a realist.
The problem for me, is that I see different accounts of what we mean by realism. I’m have no problem with the view that there’s a reality that is independent of humans, and that our descriptions (particulary scientific descriptions) of it are pretty good.
Where I disagree, is with attempts to put that in terms of truth. I don’t see that truth can extend that far.
KN,
You’re confusing the position itself with my argument for it. Here is my position again:
Epistemic likelihoods are not mentioned.