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. Erik: Classical theism is unknown to ID theorists.

    Mung: And not just to ID theorists!

    I’m quite sure KN has some awareness of it. He just doesn’t trust systems that are actually meaningful.

    Classical theism is incompatible with ID. KN probably wants to lead you to open self-contradiction. Which is funny again because he is not ashamed of self-contradictions himself.

  2. Erik: He is just being funny when resorting to the tenets of classical theism. Classical theism is unknown to ID theorists. Yet another dispute between Feser and Craig is proving this as we speak. Craig was among early proponents of Dembski.

    Yes. David Bentley Hart convinced me that most contemporary atheists do not understand what classical theism is supposed to be. Arguing against classical theism requires an entirely different strategy than simply assuming evidentialism, because the whole point of the classical theistic tradition (and indeed of classical Western metaphysics) is that there are claims that are not true by meaning alone and also justified independent of sensory experience. All of the issues debated by Aristotle, Leibniz, Spinoza, Hume, Kant, etc. are still on the agenda!

  3. Neil Rickert:

    Mung: God does not “exist.” He IS Existence Itself…

    – Alexander R. Sich

    That depends on what the meaning of “is” is.

    🙂 🙂 🙂

  4. Erik,

    More precisely, I have long been persuaded on Kantian grounds that one cannot establish metaphysics on logical grounds alone. But I also have a much narrower conception of what loguc alone can do, because I think of logic in terms of modern symbolic logic.

  5. I don’t want to lead Mung to self-contradictiion; I want to break him of his bad habit of using quotes from others in lieu of speaking in his own voice.

  6. Kantian Naturalist: More precisely, I have long been persuaded on Kantian grounds that one cannot establish metaphysics on logical grounds alone.

    I don’t know anybody who believes that you can establish metaphysics on logical grounds alone. There’s a little nuance here: Whatever metaphysics you argue for, you must argue for it strictly on logical grounds, because if you don’t, you will get illogic, and you will end up undermining whatever position you seek to maintain. Illogical people are not worth to be taken overly seriously.

    It’s true that logic does not go all the way. But it goes pretty far and it’s indispensable for what it’s meant for. You cannot argue for your position if you abandon it. You don’t even have a position worth the name if you abandon it. To your credit, you occasionally display glimpses of awareness that you don’t have a defined or sensible position. And you seem to like it this way. You shun labels, schools, systems. It would be more okay if your intellectual anarchy were less sneaky.

  7. Erik,

    I agree that we should not abandon the norms of good reasoning when we do metaphysics (or anything else!).

    I think we will be able to get by without too much mutual misunderstanding if we accept that by “logic” you mean “the norms of good reasoning,” whereas I restrict the scope of “logic” to formal systems. We will simply have to agree to disagree on the distinction between formal languages and natural languages, which I accept and you do not.

    Erik: to your credit, you occasionally display glimpses of awareness that you don’t have a defined or sensible position. And you seem to like it this way. You shun labels, schools, systems. It would be more okay if your intellectual anarchy were less sneaky.

    I’m surprised to hear that, since I always thought I was being very clear about having a defined position!

    For the record, I’m an inferentialist about semantics, a pragmatist about epistemology, a naturalist about metaphysics, a virtue ethicist about morality, and a democratic socialist about politics. Aesthetics is the only major area of philosophy in which I don’t have a defined position!

    And, for those who don’t object to wanton name-dropping, read on!

    My position is that Wilfrid Sellars and Gilles Deleuze independently figured out how to respond to Kant’s critique of Spinoza, but by using Darwin to naturalize the Kantian architectonic. Spinoza invented a flat ontology, one without any ‘verticality’ or ‘hierarchy’ — all finite objects are just different modes of the one substance, God/Nature. This gives us a radical critique of religion (which Marx and the Frankfurters developed into a critique of ideology) and an anarcho-socialist democratic politics.

    Kant observed that Spinoza’s naturalistic metaphysics was neither more or less logical than theistic metaphysics, which meant (he thought) that the choice between rival metaphysical systems could not be decided on logical criteria alone. To establish this claim more precisely, Kant argued that all cognitively significant claims required the joint use of two distinct cognitive capacities, sensibility and understanding. We need the former in order to locate objects in space and in time and we need the latter in order to apply concepts to those objects in acts of judging.

    But Kant also argues for a bright line between what can be done in any strictly empirical inquiry and what must be done by transcendental inquiry alone. Hegel and Nietzsche, independently and in perhaps incompatible ways, argued that there is no bright line: instead the whole Kantian story has be made historical and social (as in Hegel) and biological (as in Nietzsche).

    The deep reason for this is that Kant’s insight that we do not have any privileged insight into the fundamental nature of reality also applies to Kant’s own system — we do not have any privileged insight into the fundamental nature of the mind, either.

    The impossibility of cognitive privilege (i.e. the Given is a myth) means that for us today, we can think about the lived body (in Merleau-Ponty’s sense) and the space of reasons (in the left-Sellarsian sense) as replacing the purely formal/transcendental distinction between sensibility and understanding. Neither embodiment nor discourse can be investigated purely a priori. We can’t do epistemology without biology and sociology.

    The Hegelian and Nietzschean critiques of Kant come together at various points — in Adorno (to some degree), in Dewey (to some degree) but they really come into their own most adequately in Deleuze and in Sellars. Deleuze invents a Nietzschean critique of Hegel’s critique of Kant, and Sellars invents a purely naturalistic Hegel that is even more rigorous and purified of all mysticism than the naturalized Hegelianism of Dewey.

    I think that Deleuze has an extremely carefully developed process metaphysics that Sellars only hints at, and Sellars has a conception of normativity that Deleuze actually needs but doesn’t have. I think that Dewey’s emphasis on the organism-environment transaction goes a long way towards synthesizing Deleuzean metaphysics and Sellarsian epistemology.

    And I also think that the Frankfurt School’s critique of capitalism goes a long way towards explicating how cooperation — long emphasized by pragmatists as the very heart of normativity, rationality, and ethics — is threatened by a political economy that systematically rewards competitiveness and selfishness.

    I think that all makes for a pretty clearly defined position, with all sorts of labels and schools one can attach to it. How sensible it is, however, is another issue entirely — but I think it’s eminently sensible!

  8. Kantian Naturalist: For the record, I’m an inferentialist about semantics, a pragmatist about epistemology, a naturalist about metaphysics, a virtue ethicist about morality, and a democratic socialist about politics. Aesthetics is the only major area of philosophy in which I don’t have a defined position!

    A defined position would be an explanation which of these areas is most relevant and why. For example you assert that there’s some substantial difference between natural and formal languages. Are there different semantics in formal languages that are not found in natural languages? How about the relationship of languages and epistemology and the relationship of epistemology to metaphysics? How is it possible to elevate epistemology over metaphysics?

    An overall systemic consistency would be a defined position. Now, to have a defined position would presuppose a unity of reason, or at least it would acknowledge that rational coherence is valuable. If reason is not unified, then you can go all over the place in various areas and you need not have any connection between them, i.e. you would not have a defined position. You are doing pretty good as you are, better than other notable participants.

  9. Erik: You are doing pretty good as you are, better than other notable participants.

    Sometimes it’s good not to be a “notable participant,” I guess…. 😉

  10. Erik: A defined position would be an explanation which of these areas is most relevant and why. For example you assert that there’s some substantial difference between natural and formal languages. Are there different semantics in formal languages that are not found in natural languages?

    Yes. In formal languages the only relevant kind of inference is a formal inference:

    1.) The x is a F
    2.) All Fs are Gs.
    3.) The x is a G.

    is a good inference regardless of how the variables are interpreted.

    By contrast, in natural languages inferences can also be material inferences:

    1.) London is north of Paris
    2.) Therefore, Paris is south of London

    is a good inference that depends on the natural-language semantics of “north” and “south”. It’s a good inference, but not because of syntactical structure alone. Formal languages don’t have material inferences, and natural languages do. That’s a substantial difference in their semantics (and also in their expressive power), if we take symbolic logics (and set theory) as a paradigm of what a formal language is (as I do).

    How about the relationship of languages and epistemology and the relationship of epistemology to metaphysics?

    As Ray Brassier nicely put it:

    “For we cannot understand what is real unless we understand what ‘what’ means, and we cannot understand what ‘what’ means without understanding what ‘means’ is, but we cannot hope to understand what ‘means’ is without understanding what ‘is’ means.

    How is it possible to elevate epistemology over metaphysics?

    I don’t understand this question — was there a suggestion in anything I’ve said there that I do elevate epistemology over metaphysics? I certainly don’t.

    An overall systemic consistency would be a defined position. Now, to have a defined position would presuppose a unity of reason, or at least it would acknowledge that rational coherence is valuable. If reason is not unified, then you can go all over the place in various areas and you need not have any connection between them, i.e. you would not have a defined position. You are doing pretty good as you are, better than other notable participants.

    Overall rational coherence is certainly desirable, but I also think there is enough modularity to our cognitive systems that we should be realistic about how much rational coherence is achievable, even in principle, for beings with cognitive systems like ours.

  11. Kantian Naturalist: I don’t understand this question — was there a suggestion in anything I’ve said there that I do elevate epistemology over metaphysics? I certainly don’t.

    No such suggestion this time, but plenty bashing of metaphysics earlier. If you are saying that your then and now need not be connected in any way, then this speaks for itself.

  12. Erik: No such suggestion this time, but plenty bashing of metaphysics earlier.

    I was bashing metaphysics that is not grounded in epistemology, but I’ll happily bash epistemology that’s not grounded in metaphysics.

    More significantly, however, I do not think that metaphysics and epistemology should be done wholly a priori. I think that there is an a priori dimension to the metaphysics-epistemology nexus, which is best disclosed through phenomenological description of conscious experience.

    But I also think that empirical science is where the rubber hits the road, so to speak — it’s where our conceptions encounter reality, and where reality gets a vote in what we say about it. And that can lead to revising our supposedly a priori conceptions about meaning, knowledge, and reality.

    And I think this because the semantics of natural language itself shows that the distinction between the a priori and a posteriori is much more one of degree than of kind, so the two cannot be cordoned off from each other as the classical science/metaphysics, a posteriori/a priori divide would have it. Science cannot rely on a “foundation” of metaphysics because there’s no stratum of purely a priori meaning that can be investigated wholly independently of everything empirical or a posteriori.

    The whole tradition from Plato and Aristotle through Leibniz to Kant relies on that assumption, and it is deeply mistaken. Language doesn’t work the way it would have to in order for the classical science/metaphysics distinction to make any sense. Once we realize that, we can remove one of the main obstacles to revising epistemological assumptions in light of cognitive science and revising metaphysical assumptions in light of philosophy of science.

  13. Kantian Naturalist: I was bashing metaphysics that is not grounded in epistemology, but I’ll happily bash epistemology that’s not grounded in metaphysics.

    More significantly, however, I do not think that metaphysics and epistemology should be done wholly a priori. I think that there is an a priori dimension to the metaphysics-epistemology nexus, which is best disclosed through phenomenological description of conscious experience.

    To summarize, metaphysics and epistemology should be grounded in each other (i.e. this is not where either of them is really grounded), they should not be done wholly a priori, but through the lense of phenomenological description of conscious experience.

    Meaning, everything should be ultimately grounded in a posteriori phenomenology. How is this different from empiricism and even outright scientism? It isn’t:

    Kantian Naturalist:
    But I also think that empirical science is where the rubber hits the road, so to speak — it’s where our conceptions encounter reality, and where reality gets a vote in what we say about it.

  14. Erik: To summarize, metaphysics and epistemology should be grounded in each other (i.e. this is not where either of them is really grounded), they should not be done wholly a priori, but through the lense of phenomenological description of conscious experience.

    That is not at all what I said and you know it, or should.

    I said

    I think that there is an a priori dimension to the metaphysics-epistemology nexus, which is best disclosed through phenomenological description of conscious experience.

    Which clearly means that phenomenology is a priori, not a posteriori. The phenomenological description of conscious experience discloses the a priori dimension of the metaphysics-epistemology nexus: what is perception, what is action, what is thought, what is subjectivity, and what is objectivity are all phenomenologically grounded prior to their subsequent elaboration and refinement by empirically constrained modeling of causal processes.

  15. Erik: To summarize, metaphysics and epistemology should be grounded in each other (i.e. this is not where either of them is really grounded), they should not be done wholly a priori, but through the lense of phenomenological description of conscious experience.

    Also: the reason why metaphysics and epistemology are grounded in each other is because they must be correlated. We have no cognitive purchase on what is real independent of what we know to be real, nor any cognitive purchase on what it is to know independent of what knowing really is.

    We have to move dialectically between our account of what we really know and our account of what knowing really is, adjusting each in light of the other, and incorporating into our understanding of both knowledge and of reality what we learn through empirical inquiry about what sorts of things are actually real and how the process of knowing actually works.

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