The Disunity of Reason

Last night I was talking with an old friend of mine, an atheist Jew, who is now in the best relationship of her life with a devout Roman Catholic. We talked about the fact that she was more surprised than he was about the fact that their connection transcends their difference in metaphysics. He sees himself as a devout Roman Catholic; she sees him as a good human being.

This conversation reminded me of an older thought that’s been swirling around in my head for a few weeks: the disunity of reason.

It is widely held by philosophers (that peculiar sub-species!) that reason is unified: that the ideally rational person is one for whom there are no fissures, breaks, ruptures, or discontinuities anywhere in the inferential relations between semantic contents that comprise his or her cognitive grasp of the world (including himself or herself as part of that world).

This is particularly true when it comes to the distinction between “theoretical reason” and “practical reason”. By “theoretical reason” I mean one’s ability to conceptualize the world-as-experienced as more-or-less systematic, and by “practical reason” I mean one’s ability to act in the world according to judgments that are justified by agent-relative and also agent-indifferent reasons (“prudence” and “morality”, respectively).

The whole philosophical tradition from Plato onward assumes that reason is unified, and especially, that theoretical and practical reason are unified — different exercises of the same basic faculty. Some philosophers think of them as closer together than others — for example, Aristotle distinguishes between episteme (knowledge of general principles in science, mathematics, and metaphysics) and phronesis (knowledge of particular situations in virtuous action). But even Aristotle does not doubt that episteme and phronesis are exercises of a single capacity, reason (nous).

However, as we learn more about how our cognitive system is actually structured, we should consider the possibility that reason is not unified at all. If Horst’s Cognitive Pluralism is right, then we should expect that our minds are more like patchworks of domain-specific modules that can reason quite well within those domains but not so well across them.

To Horst’s model I’d add the further conjecture: that we have pretty good reason to associate our capacity for “theoretical reason” (abstract thinking and long-term planning) with the dorsolateral prefrontal cortex and also pretty good reason to associate our capacity for “practical reason” (self-control and virtuous conduct) with the ventromedial prefrontal cortex (and especially in its dense interconnections with the limbic system).

But if that conjecture is on the right track, then we would expect to find consistency between theoretical reason and practical reason only to the extent that there are reciprocal interconnections between these regions of prefrontal cortex. And of course there are reciprocal interconnections — but (and this is the important point!) to the extent that these regions are also functionally distinct, then to that same extent reason is disunified. 

And as a consequence, metaphysics and ethics may have somewhat less to do with each other than previous philosophers have supposed.

 

 

1,419 thoughts on “The Disunity of Reason

  1. fifthmonarchyman: How do you know it’s a baseless claim. Please be specific

    peace

    You’ve given us no basis for it. I’m not saying that it can have no basis, but unless you ever give us one, it’s still missing–still a baseless claim.

    It’s in your court, you owe us a meaningful basis. It’s not my job to worry about every mindless assertion that comes down the pike.

    Glen Davidson

  2. fifthmonarchyman: My hypothesis is inherently testable all you have to do is show me a consistent set of axioms that denies God and is at the same time sufficient for reason and my claim is falsified.

    vs

    GlenDavidson: You’ve given us no basis for it. I’m not saying that it can have no basis, but unless you ever give us one, it’s still missing–still a baseless claim.

    It’s in your court, you owe us a meaningful basis. It’s not my job to worry about every mindless assertion that comes down the pike.

    BURDEN TENNIS!!!!!

  3. GlenDavidson: You’ve given us no basis for it. I’m not saying that it can have no basis, but unless you ever give us one, it’s still missing–still a baseless claim.

    1) how do you know I have given you no basis for it?
    2) how do you know that I must provide a base for a claim to have one?

    peace

  4. Kantian Naturalist: BURDEN TENNIS!!!!!

    Exactly.

    For some reason the “skeptic” feels that he is owed an explanation that he finds sufficient before other worldviews are even considered with out ever being troubled to examine his own.

    It’s like a spoiled kid in a toy store demanding that the owner justify his actions before he take away the toy the kid is pilfering

    peace

  5. fifthmonarchyman: For some reason the “skeptic” feels that he is owed an explanation that he finds sufficient before other worldviews are even considered with out ever being troubled to examine his own.

    Replace “skeptic” with “Christian” and you will find even greater reluctance to consider alternatives.

    It’s like a spoiled kid in a toy store demanding that the owner justify his actions before he take away the toy the kid is pilfering

    (quoted without comment)

  6. Kantian Naturalist:

    fifthmonarchyman: My hypothesis is inherently testable all you have to do is show me a consistent set of axioms that denies God and is at the same time sufficient for reason and my claim is falsified.

    vs

    GlenDavidson: You’ve given us no basis for it. I’m not saying that it can have no basis, but unless you ever give us one, it’s still missing–still a baseless claim.

    It’s in your court, you owe us a meaningful basis. It’s not my job to worry about every mindless assertion that comes down the pike.

    BURDEN TENNIS!!!!!

    What a shame that humans have never developed the necessary logical tools to resolve such impasses.

    Now I’m just spitballin’ here, but maybe if fifthmonarchyman provided a non-circular basis for his claim, there might be some reason to take it seriously.

  7. Patrick: What a shame that humans have never developed the necessary logical tools to resolve such impasses.

    Thank God there are super-humans around to lead the humans then!

  8. Patrick:

    What a shame that humans have never developed the necessary logical tools to resolve such impasses.

    Or a website at which to employ them.

  9. fifthmonarchyman: Because God is the only sure foundation for reason

    To clarify my question , ” any “coherence” theory of truth is also implicitly theistic in that every non-Christian worldview is necessarily inconsistent at some often unexamined point.”

    Why is every non-Christian worldview necessarily inconsistent? Certainly there exist non-Christian theistic world views.

    quote:
    The fear of the LORD is the beginning of knowledge; fools despise wisdom and instruction.
    (Pro 1:7)

    In my experience many fools believe they possess wisdom and are eager to instruct others.

    My hypothesis is inherently testable all you have to do is show me a consistent set of axioms that denies God and is at the same time sufficient for reason and my claim is falsified.

    Why must one deny God? You are the expert on presuppositions but the simplest seems the best.

    Reason exists

    In order to create a particular God thru presupposition , it seems to me one must presuppose reason exists first.

  10. fifthmonarchyman:
    For some reason the “skeptic” feels that he is owed an explanation that he finds sufficient before other worldviews are even considered with out ever being troubled to examine his own.

    Do you have any links to comments that support that assertion? All I’ve seen is people ask you for the same kind of evidence that one would require for everyday activities like making an investment or crossing the street. It’s only when your god claims are being questioned that asking you to support your baseless assertions is unreasonable and you start throwing the blame for your failure to do so back on the person asking the questions.

    Before casting aspersions on others you should try actually supporting what you write.

  11. newton: To clarify my question , …

    I think a better question to FMM would be whether he thinks that logical axioms such as the law of non-contradiction are somehow Christian. And if yes, why so.

  12. Erik: I think a better question to FFM would be whether he thinks that logical axioms such as the law of non-contradiction are somehow Christian. And if yes, why so.

    If they require the Calvinist God to exist how could they be otherwise but Christian?

  13. fifthmonarchyman: My hypothesis is inherently testable all you have to do is show me a consistent set of axioms that denies God and is at the same time sufficient for reason and my claim is falsified.

    Why assume that reason requires axioms? Why assume that reason is restricted to using logic? To me, those seem obviously false.

  14. fifthmonarchyman: 1) how do you know I have given you no basis for it?

    You just have a presupposition.

    2) how do you know that I must provide a base for a claim to have one?

    You don’t. Where did you come up with the idea that I think you need one to have a claim? Having a meaningful claim doesn’t seem to interest you.

    Why don’t you actually provide a basis, rather than ask inane questions?

    Glen Davidson

  15. fifthmonarchyman: Exactly.

    For some reason the “skeptic” feels that he is owed an explanation that he finds sufficient before other worldviews are even considered with out ever being troubled to examine his own.

    KN’s idiotic comment would seem to support such evidence-free nonsense. Of course it is completely untrue that someone like myself has never troubled to examine my own views, something you like to claim without any more evidence than you have for your “worldview.”

    It’s like a spoiled kid in a toy store demanding that the owner justify his actions before he take away the toy the kid is pilfering

    It’s like an ignorant person making unsupported claims and playing burden tennis. Try something else.

    Glen Davidson

  16. Neil Rickert: Why assume that reason requires axioms?Why assume that reason is restricted to using logic?To me, those seem obviously false.

    Axiom 1: everything requires axioms. How would non logic based reasoning work?

  17. newton: Axiom 1: everything requires axioms. How would non logic based reasoning work?

    Ever watch a nonhuman animal?

  18. Logic is a fairly recent construct.

    Most reasoning is more nearly Bayesian. Concerned with likelihoods.

  19. petrushka:
    Logic is a fairly recent construct.

    Most reasoning is more nearly Bayesian. Concerned with likelihoods.

    I agree, I guess I have a less formal sense of rules of logic. Isn’t Bayesian inference a form of logic?

  20. newton: Isn’t Bayesian inference a form of logic?

    I’m sure it is, but animal learning achieves results that appear similar to what Bayesian logic would produce. My own bet is that animal learning is a combination of analog and digital. We have the digital event of neuron firing, and the analog process of firing rate.

    Anyway, it isn’t formal logic.

  21. petrushka: You think animals don’t learn?

    I have some who seem incapable but yes they learn to associate stimulus with an outcome, cause and effect. Just as humans learn don’t touch a hot stove.

  22. petrushka:
    Logic is a fairly recent construct.

    Most reasoning is more nearly Bayesian. Concerned with likelihoods.

    I do think that there’s a good deal of logic built into language. Single, dual, plural, nominative and accusative, genitive (something comes from something else), locative (here, not there–can’t be in two places at once), etc. Indeed, language might tend to make things out to be more logical than they often are.

    To be sure, there’s the “some,” the “maybe,” “probably.” Things don’t slot exactly with logic in many cases. Nevertheless, I tend to think of formal logic as being distilled from “normal reasoning,” but especially from linguistic rules.

    Glen Davidson

  23. Neil Rickert: Why assume that reason requires axioms? Why assume that reason is restricted to using logic? To me, those seem obviously false.

    And the fact that this seems so to you also proves this for everyone?

  24. petrushka: I’m sure it is, but animal learning achieves results that appearsimilar to what Bayesian logic would produce. My own bet is that animal learning is a combination of analog and digital. We have the digital event of neuron firing, and the analog process of firing rate.

    Anyway, it isn’t formal logic.

    Interesting, but is the animal reasoning?

  25. GlenDavidson: To be sure, there’s the “some,” the “maybe,” “probably.”Things don’t slot exactly with logic in many cases.Nevertheless, I tend to think of formal logic as being distilled from “normal reasoning,” but especially from linguistic rules.

    Some people here think formal languages are fundamentally different from ordinary human languages. In this opinion, they collide head-on against general linguistics. In general linguistics, language is analysed as a formal system.

  26. GlenDavidson: I do think that there’s a good deal of logic built into language.Single, dual, plural, nominative and accusative, genitive (something comes from something else), locative (here, not there–can’t be in two places at once), etc. Indeed, language might tend to make things out to be more logical than they often are.

    To be sure, there’s the “some,” the “maybe,” “probably.”Things don’t slot exactly with logic in many cases.Nevertheless, I tend to think of formal logic as being distilled from “normal reasoning,” but especially from linguistic rules.

    Glen Davidson

    I agree.

  27. Erik: Some people here think formal languages are fundamentally different from ordinary human languages. In this opinion, they collide head-on against general linguistics. In general linguistics, language is analysed as a formal system.

    Much of human linguistic communication involves connotation, and much of this involves context and tone of voice.

  28. petrushka: Most reasoning is more nearly Bayesian. Concerned with likelihoods.

    I don’t agree with that, either. I’d say that most reasoning is trial and error — see what works. Logic is just a useful tool, but is not the entirety of reasoning.

  29. Erik: Some people here think formal languages are fundamentally different from ordinary human languages.

    Yes, I’m one of those “some people”.

    In this opinion, they collide head-on against general linguistics.

    So much the worse for general linguistics.

  30. Neil Rickert: I don’t agree with that, either. I’d say that most reasoning is trial and error — see what works. Logic is just a useful tool, but is not the entirety of reasoning.

    I would say learning is like evolution. Trial an error.

    But learned behaviors approach utility as probabilities rather than as as formal results.

  31. Neil Rickert: I did make it a question.

    So you actually didn’t have a point?

    Neil Rickert: So much the worse for general linguistics.

    Shouldn’t this be a question? Because the way it is now it is a baseless assertion.

  32. Neil Rickert: I don’t agree with that, either.I’d say that most reasoning is trial and error — see what works.Logic is just a useful tool, but is not the entirety of reasoning.

    Thanks for the clarification.

  33. Kantian Naturalist: BURDEN TENNIS!!!!!

    hotshoe_: Yeehaw!

    Shhhh! That is totally inappropriate for tennis.

  34. petrushka: I would say learning is like evolution. Trial an error.

    Trial and error is purposive. Unlike evolution. Or so we are told.

  35. GlenDavidson: I do think that there’s a good deal of logic built into language. Single, dual, plural, nominative and accusative, genitive (something comes from something else), locative (here, not there–can’t be in two places at once), etc. Indeed, language might tend to make things out to be more logical than they often are.

    To be sure, there’s the “some,” the “maybe,” “probably.” Things don’t slot exactly with logic in many cases. Nevertheless, I tend to think of formal logic as being distilled from “normal reasoning,” but especially from linguistic rules.

    Exactly so. As Brandom nicely puts it, “logic is our semantic self-consciousness”. Logic makes explicit the categories that are implicit in a language. It is a metalanguage — a language that talks about language. Logic allows us to say what one must be able to do with a natural language — be able to recognize assertions, keep track of inferences, and grasp basic cognitive operations like conjunction, negation, and disjunction.

    Tomasello argues that chimpanzees are genuine reasoners: they navigate the world and solve problems with an implicit grasp of strict implication, conjunction, and negation. My current paper is about what happens to the traditional concept of human beings as the uniquely rational animal if Tomasello is right about chimps.

    There is also the further question as to how we should describe the difference between great ape reasoning and the cognitive activities of other primates and other mammals. I love my cats, but I am not so sure they infer.

  36. GlenDavidson: KN’s idiotic comment would seem to support such evidence-free nonsense. Of course it is completely untrue that someone like myself has never troubled to examine my own views, something you like to claim without any more evidence than you have for your “worldview.”

    My point above was simply this: from your perspective as an evidentialist and empiricist, the burden of proof is on FMM to establish his claims, but the default position is yours. From his perspective as a presuppositionalist apologist, the burden of proof is on you to establish his claims, but the default position is his. So both of you think that you already have the default position and the burden of proof is on the other side.

    I think I can recognize that this is the case though presuppositionalism is utterly antithetical to the version of pragmatism I prefer, which is to say that I regard presuppositionalism as relying on a utterly misguided conception of our basic cognitive situation.

    (For a contrast between presuppositionalism and pragmatism, see here.)

  37. petrushka: But learned behaviors approach utility as probabilities rather than as as formal results.

    With probabilities, you tend to get slow convergence. However, many learned activities seem to just click into place. You might later tweak them, which would be a slow improvement and could be seen as probability. But that clicking into place as a new idea does not seem at all probabilistic or Bayesian.

  38. Mung: Trial and error is purposive. Unlike evolution. Or so we are told.

    Half full or half empty.

    Brains learn as a result of reinforcement, and the concept of reinforcement can be non intuitive, just as differential rates of reproduction can be non-intuitive.

    Addiction and its unpleasant side affects are learned, but not usually the result of purpose. Lots of things are learned without intention.

  39. Neil Rickert: With probabilities, you tend to get slow convergence. However, many learned activities seem to just click into place. You might later tweak them, which would be a slow improvement and could be seen as probability. But that clicking into place as a new idea does not seem at all probabilistic or Bayesian.

    Though perhaps it could still a Bayesian process at the neurocomputational level even when it feels like “clicking into place” at the phenomenological level?

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