walto’s paper as a failed argument against Cartesian skepticism

TSZ commenter walto published a paper this year in the Journal of Philosophy entitled Epistemic Closure, Home Truths, and Easy Philosophy. Unfortunately, the paper isn’t free — if you want to read it, you’ll either need to pay for it yourself or get it via institutional access (if you’re fortunate enough to have that.)

Regarding his paper, walto made the following remark to commenter Kantian Naturalist:

I don’t know if it counts as “a refutation”–but I think keiths’ version of skepticism requires the closure of knowledge under (known) entailment [which walto refers to as ‘CLR’ in his paper.] And I think that that premise can be shown to be false.

It’s a long story and you’ll have to get my paper to see how, but the abstract is available for a nickel.

I think walto hesitated to use the word “refutation” because he couldn’t rule out the possibility of arguments for skepticism that don’t rely on CLR. Any such arguments would be unaffected by the conclusion of walto’s paper, and skepticism might therefore remain standing.  But any argument that did depend on CLR would be refuted if the conclusion of walto’s paper is correct and CLR is false.

We can (and likely will) discuss many of the technical details in the comments below, but unless I’m missing something fundamental, it appears to me to be surprisingly easy to show why walto’s paper doesn’t work as a refutation of CLR-based arguments for Cartesian skepticism.

His statement of the argument requires the following premise:

(ii) A competent reasoner sometimes knows such things as that she is sitting on a green chair.

That premise effectively amounts to a denial of Cartesian skepticism. So in order to use his argument agains Cartesian skepticism, walto first has to assume the falsehood of Cartesian skepticism just to get the argument off the ground.

The reasoning therefore ends up being circular:

1) assume that Cartesian skepticism is false;
2) using that assumption, deploy the argument laid out in the paper and conclude that CLR is false;
3) use that conclusion — that CLR is false — to negate any argument that requires CLR to be true, including arguments for skepticism.

It looks hopelessly circular to me, but walto is unlikely to take this lying down. Stay tuned for a vigorous debate.

128 Replies to “walto’s paper as a failed argument against Cartesian skepticism”

  1. BruceS
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    walto: For personal reasons, I hope you’re including political scientists in that bunch.

    Who like to picture you-know-who with a Scottish accent?

  2. walto walto
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    Lost me. Is that a Monty Python reference?

  3. walto walto
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    Regarding the keiths stuff here, I think–and you may be getting to this–that he’s actually responding to the considerably simpler NEKP argument I summarize on p. 50 (I doubt he got that far). That one is a modus ponens–modus tollens standoff, and he may say that proponents are begging the question without complaint from me.

    But…..that’s NOT my argument. And it’s not anything likely to convince anybody these days–if it ever was.

  4. Kantian Naturalist Kantian Naturalist
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    Like my students, I haven’t done the reading for today, but I do have a question about “categorialism”. Why is categorialism supposed to be a “heavyweight” philosophical thesis? How “heavyweight” it is seems to be depend on what one takes categories to be, right?

    Suppose, putting on my Sellars hat, that I say, “categories are syntactic statements in the material mode of speech” (a move that Sellars takes from Carnap). On this view, to say “a chair is a substance” is just to say “the word ‘chair’ is a noun”, and to say “red is a property” is just to say “the word ‘red’ is an adjective”. So there’s nothing terribly exciting about categories: they’re just ways of expressing in a metalanguage the grammatical structure of our language.

    It seems that if you want categorialism to be philosophically interesting, you need some account of categories that makes them not boring in the way that Carnap and Sellars did. That would seem to be an important move here. Since I haven’t read your paper, I can’t know if you made it or not. Just wanted to float that concern.

  5. walto walto
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    Kantian Naturalist,

    Good point. That’s definitely an objection I had to anticipate–and maybe could have done a better job responding to. I said this:

    …it is a controversial (and heavyweight) matter whether or not the axioms of conceptual/categorial systems always infuse many of everyday general terms and predicates. I take it that a determination of the truth-value of the thesis would involve an understanding of the process of language acquisition, the nature of assertion and presupposition, the role of concepts in thinking and communication, and countless other extremely perplexing questions.

    And I add this in a footnote:

    *I have considered some of these in my……See also Hall, Philosophical Systems; Putnam, The Many Faces of Realism, particularly the material on Carnap and the Polish Logician; and Horgan and Timmons, “Conceptual Relativity and Metaphysical Realism.” Of course, there are countless classic works on presupposition and conceptual schemes by Russell, Strawson, Wittgenstein, Quine, Davidson, Sellars, Fodor, and many others.

    So I guess in a way I’m just saying, “Well, it’s been treated like a heavyweight matter for a hundred years: it’s as controversial today as it ever was and seems not to be moving anywhere.”

    Which maybe is a cheat. But if it matters, the Thomasson/Yablo debate, which I quote a bit from, is firmly enmeshed in those issues, and neither of them seems to be budging.

  6. Kantian Naturalist Kantian Naturalist
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    Mung: I agree. And I really appreciate every time you go into the history of an idea in philosophy. The other stuff is usually too technical for me.

    Thank you for saying so! I do like being appreciated from time to time.

    I like to know what the original positions were, how they were addressed, and how they were modified to address the objections. How did we get to where we are today. Have we forgotten the past. Were original objections simply glossed over.

    It seems to me that almost every philosopher was responding to something, and unless we can decipher what position or positions they were responding to we have little hope of understanding them.

    ETA: Context is everything. Especially in philosophy.

    I agree up to a point: the history of philosophy is crucial for understanding philosophy, and that includes understanding who people were responding to. But there are degrees of understanding. One can read Spinoza, and get more out of it if one has read Descartes. And even more if one has read Maimonides and Gersonides. And understand even more if one has read . . . and likewise for Descartes, and Maimonides, and everyone else in the canon.

    (And one needs to also read philosophers who didn’t make it into the canon but who were important interlocutors in those times and places. Very few of us today know who Pierre Gassendi was but Descartes regarded him as one of his most acute critics. Likewise there were many influential women philosophers in the modern period but since they were often prohibited from publishing, their impact is known to us through their private correspondence with Descartes, Spinoza, Leibniz, etc.)

    But I wouldn’t want to get so attached to the question of origins that it over-rides everything else. I’m suspicious of the very idea that there are origins from which everything else springs. I think that there are multiple lines of influence, often conflicting, that come and go, which can be accepted, criticized, scrutinized, rejected, or endorsed.

    Plato’s originality as a thinker consisted in realizing that the antidote for the moral and spiritual corruption of Athens before, during, and after the Peloponessian War had something to do with what was right and wrong about Parmenides, Heraclitus, and post-Parmenidean philosophers.

    But that’s just specific case — I think that every philosopher who makes a genuine contribution to the conversation of humanity has to do something new with the influences to which he or she is subjected, and often has to reconcile quite different and even opposing influences.

    That said, I do think that ancient Greek and Roman Skepticism is far more fascinating than the Cartesian variant!

  7. BruceS
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    walto:
    Lost me. Is that a Monty Python reference?

    No, you have to click on the link, helpfully reproduced here.

  8. Kantian Naturalist Kantian Naturalist
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    walto: So I guess in a way I’m just saying, “Well, it’s been treated like a heavyweight matter for a hundred years: it’s as controversial today as it ever was and seems not to be moving anywhere.”

    Which maybe is a cheat. But if it matters, the Thomasson/Yablo debate, which I quote a bit from, is firmly enmeshed in those issues, and neither of them seems to be budging.

    Maybe a bit of cheat, yeah, but I’ll allow it. We all need to cheat a little bit just to get the problem down to manageable size! Thanks for that response!

    I asked because my current paper (only six days past due for the edited volume, but it doesn’t matter because I’m the editor) is about Sellars on categories, so I’m really trying to get clear on his views on this stuff. Oy!

  9. BruceS
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    walto:
    Regarding the keiths stuff here, I think–and you may be getting to this–that he’s actually responding to the considerably simpler NEKP argument I summarize on p. 50 (I doubt he got that far). That one is a modus ponens–modus tollens standoff, and he may say that proponents are begging the question without complaint from me.

    But…..that’s NOT my argument. And it’s not anything likely to convince anybody these days–if it ever was.

    Yes, I agree that is an interpretation of his argument, and as you say, that it does refer to a real circularity. I also am convinced by your points that that is not the argument the paper is making.

    To me, in the OP and several follow-ups, Keith is also interpreting your paper as arguing against Cartesian skepticism. But I think such a position is wrong. Neither the informal nor formal statements of your argument in the paper include such a conclusion. Instead, the conclusion is that “CLR is false”.

    Now perhaps Keith is saying that concluding CLR is false along with claiming the existence of easy knowledge amounts to an argument that Cartesian skepticism is false. But that would require an argument that CLR is the only way to get to Cartesian skepticism from easy knowledge. More importantly, as you argue at the top of page 42, the existence of easy knowledge is compatible with both the truth and falsity of CLR. I also think you are making this same point earlier in this thread.So if that is what Keith is arguing, then I would say his position is wrong.

    I do want to acknowledge that my posting this is somewhat unfair to Keith in that he is currently unable to respond. I trust that he will when he can do so

  10. walto walto
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    BruceS I do want to acknowledge that my posting this is somewhat unfair to Keith in that he is currently unable to respond.

    Is he? I haven’t actually been able to follow/understand the dozen or so changes that have been made to his status by Alan, Neil and Jock. I’d thought he could write stuff on this thread…but who the hell knows?

  11. walto walto
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    BruceS: Now perhaps Keith is saying that concluding CLR is false along with claiming the existence of easy knowledge amounts to an argument that Cartesian skepticism is false. But that would require an argument that CLR is the only way to get to Cartesian skepticism from easy knowledge

    Even if you needed CLR, it wouldn’t be enough. So the inference to the falsity of Cartesian skepticism would be fallacious.

  12. Neil Rickert
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    walto: Is he?

    I believe KN is correct, that keiths is now unable to respond.

  13. walto walto
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    Neil Rickert,

    Ah OK. (I think you meant Bruce, rather than KN, though.)

  14. BruceS
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    Mung: I agree.

    I like to know what the original positions were, how they were addressed, and how they were modified to address the objections.

    I read and enjoyed these both of these well-rated graphic novelizations (“comic-books” to my generation) giving overviews of events and people in the history of philosophy:

    Heretics! The Wondrous (and Dangerous) Beginnings of Modern Philosophy Interview with the authors here.

    Logicomix: An epic search for truth which is about Russell and his encounters with philosophers he worked with/argued with.

  15. walto walto
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    BruceS: I read and enjoyed these both of these well-rated graphic novelizations (“comic-books” to my generation)

    To your generation “graphic” meant there would be sex, right? 😉

  16. Mung Mung
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    says:

    Bruce, I think this might be more up my alley:

    The Cartoon Introduction to Philosophy

  17. BruceS
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    says:

    BruceS: .More importantly, as you argue at the top of page 42, the existence of easy knowledge is compatible with both the truth and falsity of CLR. I also think you are making thissame point earlier in this thread.So if that is what Keith is arguing, then I would say his position is wrong.

    I realized that preceding is not right as worded. I should have said that the referenced page in the paper and linked post show that the existence of easy knowledge on its own does not say anything about CLR and so it cannot be used to claim that easy knowledge on its own leads to Cartesian skepticism through CLR. I do read Keith as sometimes saying easy knowledge is tantamount to Cartesian skepticism.

  18. BruceS
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    says:

    walto: To your generation “graphic” meant there would be sex, right?

    Right! Another case of I-know-it-when-I-see-it.

    However, seeing it for that knowledge was hardly easily acquired in the small town where I lived in those days.

    ETA: re-arrange for better comic effect.

  19. walto walto
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    BruceS: I do read Keith as sometimes saying easy knowledge is tantamount to Cartesian skepticism.

    Not sure what you’re here.

  20. BruceS
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    walto: Not sure what you’re here.

    I ws thinkg eg of this in the OP

    (ii) A competent reasoner sometimes knows such things as that she is sitting on a green chair.

    That premise effectively amounts to a denial of Cartesian skepticism

    ETA:
    But to get from that to Cartesian skepticism, Keith seemed to rely on Closure to be true. And references to your material were meant to show that CLR’s truth/falsity was independent of easy knowledge.

    The more I post it, the less I think it was a particularly important point.

  21. walto walto
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    says:

    BruceS,

    Ah, tantamount to a denial of it.

    Yeah, no.

  22. walto walto
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    As discussed. His posts on this are pretty confused. I don’t think he really read the paper–just sniffed around a bit for a a couple of remarks he could say begged the question against a view he likes. But, of course I wasn’t claiming or trying to refute cartesian skepticism. That’d be much harder. Sellars tries to do that in empiricism and the philosophy of mind. Tough row to hoe.

    I wasn’t trying to win a Nobel Prize. (I mean if they gave them in philosophy. Weirdly, Russell got one for literature.) I’d have settled for a ‘congratulations!’ thread.

  23. Alan Fox Alan Fox
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    says:

    walto: Is he? I haven’t actually been able to follow/understand the dozen or so changes that have been made to his status by Alan, Neil and Jock. I’d thought he could write stuff on this thread…but who the hell knows?

    There’s only been one status change. Keiths is currently suspended as of 2nd August. It didn’t take effect cleanly for which my apologies. Lizzie is reviewing the situation.

  24. Alan Fox Alan Fox
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    says:

    So perhaps other members should consider not talking to an empty chair.

  25. Alan Fox Alan Fox
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    says:

    Moved a comment to guano.

  26. Kantian Naturalist Kantian Naturalist
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    says:

    walto: But, of course I wasn’t claiming or trying to refute cartesian skepticism. That’d be much harder. Sellars tries to do that in empiricism and the philosophy of mind. Tough row to hoe.

    I’d probably say that Sellars’s principle aim in that particularly essay was to refute a certain version of logical positivism, perhaps the Aufbau in particular. I do think that if one were to read a lot of Sellars, a refutation of Cartesianism would eventually come to light. (It has for me.) But man, he is a difficult nut to crack! I’ve been trying to make sense of Sellars for five years and sometimes I think I’ve got it.

    Walto, I apologize for not having congratulated you on a publication in Journal of Philosophy. That’s a really prestigious and difficult journal to get into, and an impressive accomplishment!

  27. J-Mac
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    Kantian Naturalist,

    I thought you were on nice vacation without internet access…
    TSZ is addictive?

  28. walto walto
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    says:

    Kantian Naturalist,

    Thanks, man! That Sellars paper is killer. I remember puzzling over some stuff in it about color words for days. I do think he wanted to throw out skepticism–along with the Aufbau–with his “new way of words.’

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