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.
Excellent points. I appreciate your ability to respond thoughtfully and at length to inconsequential nonsense.
Oh, Bort. I pride myself in not even trying to comprehend utter gibberish. Not everything that pretends to be “logic” actually is, Bort. If you don’t know the likelihoods, unless you demand certainty, there’s no basis for the contention that whatever they are block knowledge claims.
That this is not only not obvious to you but that you can’t learn it even after it’s been explained to you repeatedly, indicates that I’ve been wasting a lot of my time here, Bort. It’s not like anybody finds talking to you pleasant. So one has to consider the fact that (A) you can’t learn, and (B) you’re a pain in the ass, and then consider what the hell one is doing with one’s time on earth.
Yes, that was a good post of KN’s. I note that it actually does NOT agree with anything Blossom was saying. Funny how posting snippets can be misleading that way. I guess it’s some posters’ stock in trade, though.
Does it make any sense to say that any of the logically possible deceptive scenarios have any likelihood at all?
This is a conceptual point, or as Wittgenstein liked to say, a ‘grammatical’ one — not an epistemological point.
The epistemological point is to ask whether we know or don’t know the likelihoods. The conceptual/grammatical point is to ask whether it makes any sense to say that the scenarios have any likelihood.
How odd, then, that you’ve never been able to produce a rational argument for why that is the case, despite repeated challenges to do so.
Fifth has repeatedly put forth the arguments you claim he has not produced. What’s more, he has repeatedly asked for your alternative, and never gets an answer.
How odd, then, that you would make the claim that you just made.
How odd that you believe that one needs to be able to provide a rational argument for why something is the case before he can claim to know it.
Yet you can’t provide a rational argument for that claim despite repeated challenges to do so.
Reid again.
quote:
If there are certain principles, as I think there are, which the’ constitution of our nature leads us to believe, and which we are under a necessity to take for granted in the common concerns of life,’ without being able to give a reason for them; these are what we call the principles of common sense; and what is manifestly contrary to them, is what we call absurd.
end quote:
peace
His claims are justified given the all the evidence available to him, although those claims can be seen to be false from our position.
Actually, if I recall the scenario correctly, his error traces back to his being lied to by the people who tell him that the VR headset is a magical portal to a different realm. It’s not an assumption he’s making on his own; he was intentionally deceived by people who had no reason to believe would deceive him.
In fact, as I will explain below, I think it is a terrible analogy.
The concept of “non-veridical information” has not been explicated and explained. I have no idea what it could mean.
More precisely, I can conjecture many different meanings for that phrase, some of which I would happily endorse (and indeed, have done so many times at TSZ) and others which I think are badly wrong (and have argued for that at TSZ as well).
This depends on what one means by “non-veridical information”.
I think that this way of looking at things depends on having an instrument picture of the senses.
It is as if one is in a submarine, looking at electronic displays of information that purports to be correlated with features of the environment (depth, pressure, canyons, oceanic life, other vessels). One assumes that the instruments are working properly, and that the information being displayed accurately represents the real features of the environment.
In the case of the senses, of course, one cannot confirm that the senses are working properly without using them. There’s no method of confirming that they are functioning properly. In a submarine, or a car, one can detect malfunctioning sensor.
But the senses-as-instruments picture is badly mistaken. (For one thing, it leads to a homunculus fallacy, as we’ve noted before.)
The senses-as-instruments picture also presupposes mind-body dualism.
The senses as instrument picture requires that the cognitive agent be something different from the senses, in order for the senses to be instruments that the cognitive agent uses. But the senses are not detachable or separable from one’s body. To see, to smell, to hear, to touch — all of these are modes of bodily activity. (Versions of this claim can be in Aristotle, Dewey, Merleau-Ponty, McDowell, Alva Noe, and Andy Clark.) To ‘instrumentalize’ the senses is to ‘instrumentalize’ the body, which means that the cognitive agency cannot be the body.
Conversely, if one recognizes that the senses just are us, in the mode of being open to the world, then one can recognize that we are essentially and necessarily embodied cognitive agents, and to be embodied is to be sensually present and aware in our environments. Thus we can see that the analogy between our embodied sensual presence in the world and the VR headset in the Sentinel Islander thought-experiment does not work.
I would add that Descartes, in setting up skepticism about the external world in the First and Second Meditations, actually does covertly rely on an instrumental picture of the senses and thereby actually does presuppose mind-body dualism, even though the argument for mind-body dualism does not appear until the Sixth Meditation. That is but one of many vicious circularities in this supposed authoritative text of foundationalist epistemology.
Can anyone help me understand keiths’ argument, he seems to have no interest in doing so. Or is it really nonsensical gibberish? He must think its obvious and doesn’t need explaining.
I’ll take another stab:
Because I do not know the likelihood that I am or am not a Sentinal Islander that I cannot know that I am not a Sentinal Islander. Is that it?
But I do know that I am not a Sentinal Islander. So keiths must be wrong. I also know that I am not a frog, or a fairy princess. Why do I need to assess the likelihood of these things in order to know them? Has keiths said?
How odd, then, that you have provided no link to his rational argument supporting that claim.
You just contradicted yourself. 😉
Or perhaps you were just repeating yourself.
There’s no method of confirming that they are functioning properly without using them.
Not that it matters until we see a reply from keiths.
I’m not talking about Reid, as you well know since you deleted the claim under discussion. Here it is again:
“I know for certain that knowledge is impossible if the Christian God does not exist.”
— fifthmonarchyman
You make this claim often, but have never yet supported it.
I guess that’s just me being me. 🙂
Perhaps you have fifth on ignore and so haven’t yet grown tired of hearing the same argument over and over again. fifth is like the Tar Baby of TSZ.
No insult intended fifth, just having a little fun. 😉
You still don’t get it,
Believing that something is revelation does not make it so.
Not even remotely.
Something is revelation if it is revealed……
If there are any lurkers who are genuinely interested in how we can know if God has reveled something I highly recommend this
https://books.google.com/books/about/The_Arraignment_of_Error_Or_A_Discourse.html?id=rk0EAAAACAAJ
from the book
quote:
“There are many who reject the opinions of these days as errors because they will not be troubled to search and examine whether they are truths or not. We are commanded to try all things (1 Thessalonians 5:21); and how can we be grounded and established in the truth, or know truth from error, if we do not search the mind of God and learn His mind and will? 1 John 4:1: “Believe not every spirit, but try the spirits, whether they be of God or not.”
Many a truth is rejected in these days because many an error is entertained… It is not enough to say, with Pilate, “What is truth?” and then sit still, as many ask questions for discourse’s sake rather than out of a desire to be satisfied; but you must search the mind of God and inquire diligently.”
end quote:
peace
I’d like to also express my gratitude to KN for his efforts in this thread. They are in stark contrast to the approach taken by you know who.
As it happens, I’ve started reading Jay Rosenberg’s Thinking About Knowing. His first chapter is a criticism of Cartesian skepticism.
On Rosenberg’s analysis, the Cartesian skeptic assumes the following
Thus, the Cartesian skeptic would say that I know my senses are veridical only if I can rule out the possibility that they are not.
This is not quite keiths’s position. Instead keiths says
But he does not think that we can assign a high determinate probability to “the senses are veridical” because (1) there are infinitely many logically possible scenarios in which “the senses are veridical” is false, and (2) we cannot determine the likelihood of any of these scenarios.
And since one cannot assign a high determinate probability to “the senses are veridical”, one cannot know that the senses are veridical.
Tar-Baby ain’t sayin’ nuthin’, en Brer Fox he lay low. 😉
peace
Does he apply this to all knowledge claims or only some knowledge claims?
What if we apply that same claim to itself? What “high determinate probability” can we assign to it?
My point there was in the context of explicating the picture of the senses that I am rejecting.
Here it is more slowly.
If one begins with a picture of the senses as instruments, then one will find it ‘natural’ to ask, “but are my senses working correctly?” After all, instruments can sometimes fail to work correctly. The oil light will go on even if the car doesn’t need oil, if the sensor is malfunctioning.
But in those cases, we can confirm whether or not the instruments are working correctly. We can take the machine apart, test the components independently, isolate the flawed component, replace it, and see if that fixes the problem.
We cannot do that in the case of the senses, because all empirical knowledge depends on using our senses.
And since we cannot confirm that the senses are working properly, it seems to be an assumption — a claim without warrant or justification — to say the senses are veridical.
My objection here is that the very idea that senses are veridical presupposes an instrumental picture of the senses (the senses-as-instruments). I think that picture presupposes mind-body dualism, it leads to a homunculus fallacy, it is false to the phenomenology of embodied subjectivity, and it is not supported by cognitive science.
The senses-as-instruments is an article of faith.
It made sense for Descartes to adopt this as his faith, because it allowed him to reconcile his commitment to Augustinian Catholicism about the nature of the soul with his commitment to mechanistic/mathematical physics about the physical world. The senses-as-instruments is how the ‘ghost’ talks to the ‘machine’.
I’m less sure that the senses-as-instruments is philosophically well-motivated once the ghost in the machine has been replaced with a machine in a machine (as it seemingly would be, according to keiths’s own reductive physicalism).
I don’t know.
I myself think it is a good principle in some epistemic contexts, but not others.
I think that justification is context-dependent. What kinds of reasons are appropriate depends on the kind of claim being made, the situation in which the claim is made, to whom it is made, and for what purpose.
Put otherwise, different kinds of conceptual frameworks stipulate different criteria of justification. In the context of mathematics, justification is deductive validity. In the context of theoretical physics, justification is measurability of the implications of models. In the context of ordinary perceptual knowledge, justification is more-or-less reliable perceptual reports about sensible characteristic at space-time regions.
There are some contexts in which “S knows p only if S can assign a high determinate probability to p” is a good rule to follow. I think this is particularly salient when it comes to the impact of social science on public policy.
More specifically, I think that we’d have better public policy in the US if we were guided by the negative version of this claim: “If S cannot assign a high determinate probably to p, then S does not know that p”.
Cute, but applying any epistemic principle to itself will generate paradox. That’s not an objection to keiths’s principle per se.
I don’t know
I would disagree here.
There is one epistemic principle that won’t generate paradox when applied to itself.
It will instead produce a self-reinforcing regress centered on the true source of knowledge.
peace
Imagine our North Sentinel Islander being presented with sensory information of a cow. Forest-dwelling people apparently have difficulty in comprehending large objects at a distance as they never experience such phenomena in their daily life. “What sort of insects are those?”
Nothing much is known of North Sentinel Island culture but I suspect there has been no domestication of large mammals. I’m not sure if there are feral pigs on the island. So what does the Sentinel Islander (having been persuaded to don the VR helmet) make of the virtual cows. Can he touch and smell them? Do they lick or kick him? Seems we are performing the same brain-in-a-vat experiment wearing a different dress. Still pointless.
ETA thanks to mung for spotting the spelling error. 🙂
The Father Ted fallacy:
link
marge lammals?
Bingo. Well done.
Now, one might say here that one person’s modus ponens is anothers’ modus tollens, and claim a stalemate. But the thing is those who think we do know such things as our names have a consistent outlook on the world, while those who think we don’t know anything can’t explain why the hell they’re talking to us at all. Their whole “world” is a bumble. They use words entirely differently from everyone else–except when they don’t (which is every minute they’re not pretending to be skeptics).
So, as KN has said, we take a look at the two worlds, and decide that modus ponens is right–we DO know stuff, and the modus tollens people are nuts.
walto,
Sure we can. There’s no reason to stop interacting with the world just because you acknowledge that it might be virtual, not real.
We use “knowledge” the same way as non-skeptics, to refer to justified true belief. The difference is that we are honest about what we can and cannot know.
In other words, you assume your conclusion. I prefer to think things through.
Also, you keep describing the skeptical view as “nuts”, yet whenever you try to point out inconsistencies or errors in it, you fail (as we just saw).
It must be frustrating to regard a view as crazy, only to be reduced to sputtering when you’re asked to provide an argument to that effect.
Excellent summery.
The modus tollens people do serve an important purpose though.
They remind us that there must be a foundation behind it all.
We do know stuff the question is “how do we know?”
peace
Well, I’d still like to give keiths the benefit of the doubt.
(How ironic is that?)
I’m probably missing some crucial distinction.
I’ve been spending a little more time in Huemer’s Skepticism and the Veil of Perception. Part 1 of Chapter V is “What Is Perceptual Knowledge?”
Perhaps keiths’ skepticism only extends to our senses and our perceptions of the external world and my claim to know that I am not a frog, or a fairy princess, completely miss the point because I am not perceiving myself to be “not a frog” and .I am not perceiving myself to be “not a fairy princess” and therefore I cannot be fooled or otherwise mislead by my perceptions with respect to those claims and therefore I can actually know that I am neither.
But I still think I can know that there is cheese I my fridge regardless of whether I assess the likelihood of whether or not there is cheese in my fridge. If I believe there is cheese in my fridge, and there is in fact cheese in my fridge, then I am justified in my belief, and can say I know there is cheese in my fridge, regardless of whether it is possible that God may have eaten my cheese.
Likelihood’s got nothing to do with it.
If I open my refrigerator door and don’t actually see the cheese I can still know there’s cheese in it even if I don’t sense or perceive the cheese.
It does not follow though that you are not nuts. 😉
fifth,
Heh. Print that out and tape it to your monitor.
One does not need a reminder taped to a monitor to remind one of what one already knows.
I love it when keiths encourages people to engage their senses/perceptions.
He always manages to act like our senses/perceptions can be trusted.
I’d sure like to know how that works, exactly.
To quote Jay Rosenberg:
“On the face of it, I still know many things which imply, both severally and together, that I am not a brain in a vat having the sensory experiences characteristic of someone sitting beside a fireplace. And one person’s modus tollens is still another person’s modus ponens. It is equally valid to reason from the premise that I do know that I am seated by a fireplace to the conclusion that I do know something which implies that I am not a brain in a vat. Just as we earlier needed to see an independent reason to accept the skeptic’s premise that I do not know that I am a brain in a vat, we now need to see an independent reason to accept the skeptic’s new premise that nothing that I do know implies that I am not a brain in a vat.”
The chief difficulty with Cartesian skepticism (not necessarily keiths’s own view by that name) is that it disengages us from appealing to all the things that we do ordinarily take ourselves to unproblematically know in order to generate the conclusion that one cannot distinguish between veridical and non-veridical sensory episodes — perceivings and ostensible percevings — in terms of the intrinsic characteristics of those sensory episodes.
But this disengagement should not be taken for granted. The Cartesian skeptic needs to provide an independent reason for why the whole background of ordinary justified beliefs ought to be suspended when determining the veridicality of any particular sensory episode. Descartes himself does not provide one, but rather observes that if one does so, then skepticism about the veridicality of the senses follows.
It does so, however, only because the entire project consists of withdrawing from embodied engagement with the world and with other subjects with whom one shares that world. Without the epistemic support of bodily activity and intersubjectivity, skepticism about the senses does follow, just as an inability to distinguish between fantasy and reality is occasioned by sensory deprivation and social deprivation for prisoners in solitary confinement.
KN:
My skepticism doesn’t depend on #1.
Again:
I don’t think that’s right. If you are firmly convinced that there’s cheese in your fridge, and there is in fact cheese in your fridge, then it just happens to be the case that your confidence aligns with a fact about the world. That does not make you justified in your belief; it just means that your belief has happened to be true. Justification requires that you are capable of providing reasons or grounds for your belief, in circumstances where doing so is important.
Can I suggest that folks don’t keep cheese in their fridge – or at least allow it to reach room temperature before eating it. If not, you are going to miss a lot of flavour.
ETA: I recommend something like this.
Exactly.
If I believe that there is cheese in my fridge because the cheese fairy sneaks in and places it there just before I open the door then my belief is not justified even if there happens to be cheese in the fridge.
How do you know you are in a circumstance where providing a grounds is important?
peace
I think it does. It has to be the case, for skepticism about the senses to work, that it is at least conceivable that there are worlds at which no one has veridical senses.
The question we have not been inquiring is this: what does “the senses are veridical” mean?
I can think of many senses in which it is obviously true, and others in which it is obviously false.
The most natural way of parsing the idea is that it involves conflating sensory episodes — which are non-conceptual states of the perceiver– with perceptual judgments — which are conceptual. And then, in addition, accept a correspondence theory of truth in which a conceptually structured proposition is true if and only if it corresponds to some fact or objectively existent state of affairs.
The idea would then emerge “the senses are veridical” if and only if all (most? some?) sensory episodes correspond with some objectively existent state of affairs.
Needless to say, I do not treat this as the best way of understanding either the nature of perceptual experience or the role of ‘truth’ in epistemic conduct.
Rather, I think that sensorimotor abilities are just reliable guides to detecting and classifying salient features of our environments. They are reliable by virtue of the complex causal relations between (1) the features of our environments, (2) the sensory episodes (occasions of sensory capacities) normally caused by those features, and (3) the conceptual episodes (occasions of conceptual capacities) that are both guided by those sensory episodes and which refer to or intend the features of the environment that have caused those sensory episodes.
(Since the sensory episodes are normally caused by features of the environment, but not necessarily so, it is possible for there to be hallucinations or other kinds of non-veridical seemings.)
I don’t have a settled view on truth, but I am strongly inclined to accept some version of deflationary treatments of truth as a semantic notion. I do not think that truth makes sense as a goal of any finite epistemic activity, though I do think that something like Sellars’s CSP (“Conceptual System Peirceish”) is a regulative ideal of epistemic activity, and I find “picturing” a useful way of thinking about the representational dimensions of cognitive activity in the context of causal explanations of that activity.
Typically, it’s when one someone asks you a question.
More specifically — since justification is context-dependent — it depends on both the attitudes taken towards the belief and the significance of the implications of the belief, esp. on conduct that affects other people.
If I believe X, and I think that people who don’t believe X should be imprisoned or fined, and it is important to me that other people believe X, then I had better have reasons for believing X that can pass muster in the tribunal of public reason — or else I’m just willing to be a totalitarian dictator.
It’s American cheese. There’s not much flavor to miss.
KN,
Well, in reality we either are, or aren’t, in any particular Cartesian scenario (assuming it is well-defined). So the likelihoods we’re talking about are purely epistemic. They reflect our state of knowledge, not the state of the external world. They can vary, in principle, from observer to observer.
When I say that we don’t know the likelihood that our perceptions are veridical, I mean that we can’t, on the basis of our knowledge, produce a determinate assessment of the epistemic likelihood.
Whether you prefer to think of this as
1) we don’t know the epistemic likelihood, or
2) we know the epistemic likelihood, and it has the value ‘indeterminate’, or
3) the epistemic likelihood doesn’t exist at all,
seems immaterial to me.
For any of the three, the result is the same: a knowledge claim is illegitimate. You can’t legitimately claim to know something without knowing that it is likely to be true.
I would agree. That is the case even if it is myself who is asking me the question.
peace
My point was that I don’t even understand what it would even mean to apply the concept of “likelihood” to a merely logically possible world, independent of any reasons to consider that world as adjacent to ours in any relevant respects.
(Maybe I fell into that trap myself when I began this line of thought months ago, in my initial criticism of Musk.)
With regard to “the state of our knowledge,” all of our knowledge either presupposes or vindicates the reliability of our perceptual capacities. Without those, there’s nothing left to call knowledge.
I know that you’ll demur, that there’s no “knowledge” but plenty of “knowledge*”. As you observe, the most ardent Cartesian skeptic will still swerve to avoid being hit by a car. But I draw a different conclusion from this: that what you call “knowledge*” is all there ever really was to “knowledge”, because knowledge is itself a matter of practice or conduct.
The idea that there’s some other thing besides practical conduct for our knowledge-claims to be about is itself a Platonic/Christian illusion, and one that we are better off without. Knowledge as grounded in sensorimotor abilities, in specific cognitive-epistemic activities, is all that there is to the very concept of knowledge, once we’ve let go of the Platonic/Christian ambition for transcendence.
KN @ 36:
Yeah, I thought of that after I posted but decided to just live with it and admit I made a mistake if someone brought it up. Thanks for bringing it up! 😉
It would be nice if keiths admitted that the dispute is over justification.
This isn’t France, we have electricity here.
I’ve ordered the book.
Huemer has a discussion of brain in vat but i’m uncertain as to the relationship between a BIV argument and the Sentinel Islander argument.
Is the Sentinal Islander argument supposed to offer some advantage over a BIV-style argument? Does it avoid any difficulties that come into play with a BIV argument?
Thoughts?
Thanks
Exactly right.
by keiths logic: the failure of keiths to answer a question means that keiths is afraid to answer the question.
Oh good. Thanks for settling that dispute. Deductive logic out the window!
How likely is it that your claim to know this is true and how did you ascertain the likelihood? Or should we just proceed as if we have no reason to believe that your claim is true because it is no more likely to be true then false?