Consilience and the Cartesian Skeptic

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.

keiths:

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.

317 thoughts on “Consilience and the Cartesian Skeptic

  1. keiths: You’re confusing the position itself with my argument for it. Here is my position again:

    Any knowledge claim based on the veridicality of our senses is illegitimate, because we can’t know that our senses are veridical.

    Epistemic likelihoods are not mentioned.

    In that case, I do think that your position is incompatible with any kind of skillful coping with one’s environment.

    If we take (as I think is the only defensible position) an animal’s skillful coping with its environment as the sparest, leanest kind of knowledge that there is [effectively taking Dewey’s position that all savoir is savoir-faire], then the second-order question of legitimizing our epistemic practices according to norms of reasonableness must acknowledge that the reliability of our sensorimotor abilities, both innate and acquired, is a constitutive principle of all inquiry.

    The question of “but how do we know that our senses are reliable?” presupposes an epistemic position other than the one than any finite embodied/embedded cognitive agent could possibly occupy, which is to say, the position that could only be occupied by God or a God-substitute. (As indeed it does for Descartes, on any acceptable reading of the Meditations.)

  2. KN,

    In that case, I do think that your position is incompatible with any kind of skillful coping with one’s environment.

    Not at all.

    It’s possible to cope skillfully with a virtual environment as well as a real one. Ask any gamer.

  3. keiths: You’re confusing the position itself with my argument for it.

    The position is a non-sequitur. That leaves the argument. Folks have been very kind to look at the argument not the position. Take that from them if you must. But replace it with something that’s more then a position.

  4. KN,

    You make a similar error here:

    It does so, however, only because the entire [Cartesian skeptical] project consists of withdrawing from embodied engagement with the world and with other subjects with whom one shares that world.

    That’s not true. I fully retain my embodied engagement with the world, but I acknowledge that it might be a virtual world, not a real one.

  5. keiths: It’s possible to cope skillfully with a virtual environment as well as a real one. Ask any gamer.

    Another non-sequitur.

    Even if it is the case that it’s possible to cope skillfully with a virtual environment as well as a real one it does not follow that your position is not incompatible with any kind of skillful coping with one’s environment.

  6. keiths: Epistemic likelihoods are not mentioned.

    How convenient. It’s likely they would appear in the missing premise were you to ever provide it.

  7. keiths: All I know is that in this world — whether it’s virtual or real — the two philosophy PhDs have failed to present effective arguments.

    They laugh at you. Shake their heads at you. Say they are done with you. But that matters nothing to you. Even though they have a PhD in philosophy and you blow dust off computers..

  8. KN,

    In your lengthy Peirce quote, the error is easy to spot:

    …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.

    He won’t be led to “the one True conclusion” if the senses are non-veridical. Peirce asssumes the veridicality of the senses while providing no justification for that assumption.

  9. keiths: He won’t be led to “the one True conclusion” if the senses are non-veridical. Peirce asssumes the veridicality of the senses while providing no justification for that assumption.

    So?

    I thought you had made it clear that you are not questioning the veridicality of the senses? Am I deceived? Why is it only now that you demand justification for the veridicality of the senses?

    Perhaps the VR goggles are delivering veridical information after all and you have no justification for claiming that they are not. Perhaps you captured a senseless Sentinel Islander and just didn’t know it, what with the Islander being an object in the external world and all.

  10. KN,

    To reject the hypothesis that there are Reals that affect the mind in lawful ways is to reject all hope of dialectically stable inquiry.

    Cartesian skepticism doesn’t require one to reject that hypothesis, and I don’t. Reality can “affect the mind in lawful ways” even when perception is non-veridical.

    …one cannot seriously inquire without committing oneself to the veridicality of the senses.

    That’s simply false. Science is in the business of discovering regularities, and nothing prevents a virtual world from displaying regularities.

  11. keiths: Cartesian skepticism doesn’t require one to reject that hypothesis, and I don’t. Reality can “affect the mind in lawful ways” even when perception is non-veridical.

    But you don’t claim that perception is non-veridical. Don’t you object every time someone accuses you of claiming that perception is non-veridical? Don’t you say they have misunderstood your argument?

    Or have you forgotten just what it is that you’ve actually said, over these many threads?

  12. keiths: Science is in the business of discovering regularities, and nothing prevents a virtual world from displaying regularities.

    Absent a real world there is no content to the idea of a virtual world. How do you, as a Kartheisian Skeptic know there is a real world? You don’t.

  13. keiths: Science is in the business of discovering regularities, and nothing prevents a virtual world from displaying regularities.

    I see that as a mischaracterization of science. And that has a lot to do with why I don’t find virtual world thought experiments to be at all persuasive.

  14. Various peeps have brought up deduction. I’m going out on a limb and saying.. there’s no such thing (If you’re honest with your priors).

    For example, Uniformity of nature is primary and pervasive.. and its INDUCED.

  15. Richardthughes,

    As KN mentions above, there is also (Piercian) abduction that is often summarized as “inference to the best explanation”.

    ETA which is why I keep asking where Keiths’ obsession with the idea that his senses might not be reliable gets him. What can we abduce? There has been deafening silence on this.

  16. keiths:
    It’s possible to cope skillfully with a virtual environment as well as a real one. Ask any gamer.

    Until the healer lags and the party wipes.

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