Lately I’ve been reading Outline of Pyrrhonism by Sextus Empiricus. Sextus collects the arguments for Skepticism as practiced by ancient Greek and Roman philosophers. Since the notion of “skepticism” seems to play some small role here, I thought it would be fun to take a look at what Sextus means by it.
Sextus situates skepticism as the only reasonable response to “dogmatism”. The dogmatists he has in mind are Platonism, Stoicism, Epicureanism, and Aristotelianism (“the Peripatetics”).
He observes, firstly, that the dogmatists all contradict one another — if Stoicism is right, then Epicureanism must be false; if Epicureanism is right, then Aristotelianism must be wrong, etc. What are we to do when dogmatism contradicts dogmatism?
Sextus then observes that none of these positions is “self-evident”, because all of them requires “going beyond the appearances” by making claims about what is “nonevident”. In order to do make claims about what is nonevident, the dogmatist must always either make a circular argument that assumes what they purport to establish or commit themselves to an infinite regress. On this basis he concludes that it is not reasonable to make claims about reality one way or the other. Instead the Skeptic endeavors to live only according to the appearances, and be guided only by what is immediately evident to the senses.
A nice corollary of Sextus’s arguments is that one cannot be a naturalist and a skeptic, since the naturalist does make positive claims about the nature of reality. Naturalism and theism effectively cancel each other out.
The dialectic between dogmatism and skepticism stretches out across the whole history of philosophy. The re-discovery of Stoicism and Epicureanism during the Renaissance re-activated the ancient quarrels between competing dogmatisms (though with a different political dimension, since by this time Aristotelianism had become, thanks to Aquinas and subsequent theologians, the official doctrine of the Catholic Church, which its entrenched power structure). So the quarrel between competing dogmatisms had a political dimension that it seemed to have lacked in antiquity. The revival of Skepticism, most notably (to my mind) with Montaigne, then leads to renewed efforts to establish dogmatism by refuting Skepticism. (This did not prevent some philosophers from attempting to integrate Christianity and skepticism, as Pierre Gassendi did.)
Descartes was, as we know, the most famous (or infamous) of attempts to refute skepticism. But as was pointed out even then, Descartes’ arguments do not avoid circularity. (I believe it was Antonin Artaud who first made this point in first, in his Objections to the Meditations. Descartes’ Reply is, to put it mildly, not convincing.)
The inconsistencies within Cartesian dogmatism led to multiple and contradicting attempts to repair it: Spinoza, Leibniz, Malebranche, and Berkeley being the attempts that have since made it into the Canon (largely because they were all men). At the same time, Pierre Bayle is collecting the new Skepticism into what amounted to a new version of Outlines of Pyrrhonism for the modern era. Following on the heels of all of them, it fell to Hume in his Treatise on Human Nature to demolish all permutations of modern dogmatism by destroying their basis in Cartesianism.
Since then, the dialectic runs back and forth between competing dogmatisms and between dogmatism and skepticism. Kant was perhaps the first philosopher to even attempt a genuine via media between dogmatism and skepticism, but the fatal problems with Kant’s solution are well-known to most casual students of philosophy.
To this day it remains unclear whether there is a via media between dogmatism and skepticism. Some philosophers, including myself, think that the historical arc of pragmatism that runs from Hegel through Peirce and Dewey to Sellars should be understood as precisely an alternative to both dogmatism and skepticism. Others, of course, are not convinced. And so we have the persistence of both multiple forms of dogmatism — naturalism and theism alike — as well as new forms of skepticism.
Can a naturalist be a skeptic? Is skepticism more reasonable than any competing dogmatism? Is skepticism a viable philosophy as a way of life? Is pragmatism a dialectically stable alternative to dogmatism and to skepticism, or must it collapse into one or the other?
Robin,
It’s suspect because, you know, it’s raising someone from the dead that seems to have seriously died and stayed dead.
And, even though it was the king of Jesus’ miracles, the synoptic Gospels ignored it completely. John is the least believable of all of the Gospels, being late and obviously trying to show Jesus in as exalted a manner as possible.
The story of the resurrection of Lazarus may well be a take-off from the story of the rich man and Lazarus, in which it is claimed that even if someone was raised from the dead “they would not believe.” Kind of a typical claim, never tested with authenticated miracles.
Glen Davidson
JW, I believe. Possibly even less believable than the LDS leadership.
Glen Davidson
Is that right, J-Mac? You’re a Jehovah’s Witness?
I guess you failed to actually read my post. I told you what it would take, and there IS a set of conditions that would succeed. At no point did I say that no matter what is presented it has to be rejected. I simply don’t work like that, that is just a story you try to tell yourself to suppress the fact that your own gullible standards look patently irrational in comparison.
Yes, that’s me, biased towards not gullibly buying into bullshit, and requiring a rational level of justification for extraordinary claims.
Actually I have. What I explain there is, in point of fact, evidence that the origin of life was a natural process. It’s not conclusive proof to be sure, but it is evidence nonetheless.
Besides, those two situations aren’t analogous at all. If a person were to just claim to me that he has made the origin of life happen in his “lab” somewhere, I also wouldn’t believe him. At minimum, the claim would have to be reviewed and the process repeated by scientists actively trying to test and falsify the claim. If the greater scientific community would eventually get to a consensus that, yes, his experiment shows an example of the origin of life and they could replicate the results, I would accept it too.
What does that even mean? How would a brain scan reveal angel images in the brain?
The point is I could have a tumor or hemorrhage in my visual cortex, or another brain-area known to produce hallucinations or delusions with religious content, like people who suffer certain epileptic seizures get.
God is in control. So the conditions are controlled.
You are still missing everything (smilie).
Yes, measurement is old. I would put it back at somewhere near the origins of life. Measurement is central to everything.
The problem is that people think measurement is old, and therefore we can take it for granted and largely ignore it.
So people study consciousness, with the understanding that consciousness is logic, and we can ignore measurement. By contrast, I say that consciousness is measurement, and we can (more or less) ignore logic. People cannot understand consciousness, precisely because they put too much emphasis on logic, to the extent that they have made logic a religion. But there is very little to logic itself. Logic can be done by an inexpensive silicon chip. Measurement is what keeps us in touch with reality.
Neil Rickert,
The oldest type of measuring is comparison.
I do not agree with that.
Comparison is a perceptual activity. But measurement is prior to perception.
Ok.
Fair enough, but that’s not what I think, nor is it reflected in any of my responses above.
To the point – I was responding tangentially to Erik’s question regarding what category measurement belongs to. So while your elaboration on science starting with measurement and coming up with creative ways to measure things is certainly
accurate, it wasn’t what I was addressing. So, I’m not sure where the dispute in what I posted lies.
Again, perfectly fine, but not what I was addressing at all.
More than enough to get someone hanged.
Only if you claim E. coli is perceptive when comparing past and present nutrient level, in order to “decide” to run or tumble.
It cannot compare past and present nutrient level. It only has present nutrient level to go on.
Maybe it can compare current nutrient level with some kind of memory or representation of past nutrient level. But forming that representation is a kind of measuring (perhaps very primitive measuring). So measuring is still prior to comparing.
Yes, that must be the process, some kind of chemical memory and an algorithm that, on comparing current and immediately previous nutrient level, outputs “run” if “higher” and “tumble” if “lower”.
Maybe it’s just a different way of saying the same thing. Most measuring today involves comparison with an agreed or defined standard. There’s still a physical standard kilogram in Paris.
But most measurement does not compare with that standard. We use the standard to calibrate our tools. But then we use our measuring tools directly without doing further comparisons.
And when folks were doing folk science no agreed International standard was needed. Just pick an arbitrary unit: a foot, a pace, an elbow – and you can do some pretty sophisticated setting out. It seems like comparison to me.
Sure.
Maybe at one time. But now, we know so much more!!
“Rev. Boxley Fryer
Pastor, US’s Largest Non-Floridian Megachurch”
🙂
KN,
Any response to this?
KN,
There’s another quite serious problem with your rejection of the correspondence theory of truth: it only obscures, but doesn’t eliminate, the skeptical problem you face.
I asked:
You responded:
Applying that same logic to the Sentinel Islander thought experiment, you are claiming that the Sentinel Islander’s beliefs about LaLa Land are actually true, not because they correspond to the actual state of affairs — they obviously don’t, since there is no LaLa Land in reality — but because they allow the Islander to successfully navigate the fictional LaLa Land.
The skeptic points out that the Islander’s perceptions of LaLa Land, depending as they do on the inaccurate information delivered by the VR headset, do not correspond to the actual state of affairs. Instead of contesting this, you simply redefine what ‘true’ means so that it no longer depends on the actual state of affairs. It’s a purely semantic move, and it does nothing to address the underlying problem, which is the disconnect between the Islander’s perceptions and reality.
Why are you bringing up this nonsense again?
You’re appealing to an imaginary world to support a correspondence theory of truth? Cool!
The problem isn’t with the Sentinel Islander, it’s with the Virtual Reality world. It is the VR world that doesn’t correspond with reality.
Poor Mung. Hopelessly lost again.
But at least he got to post another comment and get some attention, so his goals here are met.
The theistic theory of truth (which is what your correspondence theory appears to be) works quite well here. That’s because you are able to appoint yourself as God for the purposes of this thought experiment.
But this does not generalize to other situations.
Correct.
Neil,
Hardly. You think that only a God could know that a VR headset’s output cannot be blindly trusted? Give me a break.
KN,
Seriously? You don’t see the obvious problems with Mung’s argument?
Didn’t think I needed to point out the obvious, but apparently it’s necessary, since KN can’t see what’s wrong with Mung’s argument.
Mung:
The problem is with the Sentinel Islander, who assumes that the output of the VR headset is an accurate depiction of reality. That assumption isn’t justified, and in fact the output of the headset isn’t accurate.
Anyone who assumes that our perceptions paint an accurate picture of reality is making a similar error.
Hence Cartesian skepticism.
I’m a skeptic about that whole VR scenario.
However, assuming a virtual reality, then there should be a virtual truth, which would be what matters to participant in the virtual reality. However, you are insisting on the truth as seen from the outside (the “God’s eye” or theistic version of truth).
Neil,
The Islander takes it to be the real truth, not a “virtual truth”. The Islander thinks that LaLa Land is a real place that possesses the characteristics revealed by the VR headset. It isn’t.
The Islander got it wrong, and the mistake is obvious, as I pointed out above:
You don’t have to be God to realize that a VR headset can “lie”.
Give it up, Neil. You got confused and conflated objectivity with divinity. You’ve been making this goofy mistake for months, and it’s been pointed out again and again.
Accept it and move on.
I don’t have anything to give up. You are the one with that problem.
Actually, no. That’s what you are doing. But you are unable to see it in yourself.
And I got another reply from you. And now all we need is Patrick to make the circle complete. It’s pretty obvious that you have nothing. So why not just keep your mouth shut?
And even I can see you’ve gone off on another tangent. It’s a constant shell game with you. You’re supposed to be defending a correspondence theory of truth. Remember? If the VR sim doesn’t correspond with reality it doesn’t help your case.
Mung.
No, that’s just your confusion again.
I’m showing that KN’s rejection of the correspondence theory, despite his hopes, does not solve his skepticism problem.
The correspondence theory of truth is just one of the premises I reject on which keiths’s version of Cartesian skepticism depends.
I also don’t think that the proper function of sensorimotor abilities is analogous to asserting, which means that even if the correspondence theory of truth could be made to work for assertions, it still wouldn’t vindicate the very idea of “the veridicality of the senses.” It’s because the function of our sensorimotor abilities is not analogous to asserting that I don’t follow keiths in treating reliability of our senses in terms of their veridicality.
It’s also worth stressing that unlike keiths, who writes of “the senses” as if they were passive receptors of atomic sense-data, I talk about “sensorimotor abilities”, which emphasizes the role of bodily action in perception. (For more, see Nöe’s Action in Perception.)
And whether the correspondence theory of truth can be made to work depends on whether we need anything from a theory of truth beyond an explication of the inferential norms governing the predicate phrase “is true”. Maybe we do need more than that, but it’s not immediately clear as to why.
Kantian Naturalist,
Thanks. That seems about right to me.
KN,
No. As I explained above, your rejection of the correspondence theory doesn’t eliminate the problem of skepticism. It’s a purely semantic exercise. You’ve simply redefined the meaning of the word “true” so that the Sentinel Islander’s beliefs can be said to be “true” while still not corresponding with reality.
KN,
I ask you if the keys are on the kitchen table. You employ your sensorimotor abilities by walking to the doorway and looking. You reply: “Yes, the keys are on the kitchen table.”
Your visual sense tells you that the keys are there. That perception is the basis for your reply.
KN.
I see perception as an active, not a passive, process.
That doesn’t change the fact that your belief that the keys are on the kitchen table is due to your perception that the keys are on the kitchen table. Your visual sense tells you that the keys are there.
If what the Sentinel Islander is experiencing isn’t real, what is she having an experience of, exactly?
Mung,
The experience is real, but his interpretation of it is faulty. He’s receiving (and misinterpreting) the information he receives from the VR headset.
Are we approaching brain-in-a-bottleness?
Suppose every sensory input is manufactured by some hyperdimensional kid as part of a video game. The game console is sophisticated enough that we never experience any disconnect between sensation and perceived reality, except for illusions and such that we can study and attribute to “design” shortcomings.
What I think you are saying can be summed up by considering feedback and consilience. Imagine the “brain-in-a-vat scenario” with you or I as the brain, having previously had the experiences we’ve had in reality, then kidnapped, drugged, dissected and dumped in the vat. What would be needed to simulate perfectly our previous existence so perfectly we would be unaware of the least anomaly?
I suggest every sensory neuron would need to receive consilient inputs. Not just the optic nerves but the whole panoply of inputs, auditory, body posture, all the skin receptors, information about breathing digestion and so on. Then outputs would have to coincide with that body posture and movement and interactions with the terrain. Imagine walking briskly uphill on uneven ground on a sunny but windy day and all the feedback necessary for us to adjust posture to lean into the wind while looking out to avoid tripping over rocks.
Needs a bit more than a VR helmet.
Take a commercial pilot flight trainer. To get anywhere near the actual experience of flying, the feedback, swinging the cabin module around to match in with the change in acceleration normally experienced when climbing, turning etc. requires a high level of sophistication.
It’s more than just visual if you want to create believable VR. Sound, smell, vibration and feedback, touching what you see etc.
petrushka,
The Sentinel Islander thought experiment stops well short of that, and deliberately so. I didn’t want people confusing it with a brain-in-vat scenario. They are analogous but nowhere close to being identical.
Alan:
That’s why petrushka specified “every sensory input”:
Just for the record, I don’t mean to say that the Sentinel Islander has ‘true beliefs’ (or ‘false beliefs’) about what he experiences when he looks through the VR device. I don’t really have an opinion about the case one way or the other and I don’t see the value of talking about it.
My main contention has been that it’s a bad analogy for perception, so it doesn’t help establish that Cartesian skepticism is correct.
Cartesian skepticism begins with the assumption that the proper function of the senses is to disclose truths about the world, but then argues that since we can never confirm whether the senses are playing that function correctly (since it would be circular to use the senses to verify the senses, etc.), we’re never fully warranted in our belief that the senses are veridical.
Whereas I simply don’t think that the proper function of sensorimotor abilities is to disclose truths about the world in the first place. The “veridicality of the senses” is not an issue for me, because I think it relies on a mistaken conception of the role of perception in cognition.
Feedback. It requires interaction with the internal model. Taking a virtual step tests the virtual model.
Alan:
Which is why, in my OP on the thought experiment, I wrote:
Didn’t you ever get around to reading it?
KN,
Any response to this?