Tag Archives: Thomas Nagel

Nagel's Mind and Cosmos, Objective Value, Delong and Blackburn

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I have trouble understanding why critics of Thomas Nagel's Mind and Cosmos are coming down so hard on his belief that value statements---particularly ethical ones, can (some of them, at any rate) be objectively true or false.  I'll consider two examples here.  Brad DeLong's objection seems to me based primarily on his continued mistaken view that Nagel views his reason as infallible.  It's therefore not specific to the case of moral or other value judgments.  Simon Blackburn's objections are more interesting because they are more specific to value judgments, and better address Nagel's actual position.

Brad DeLong seems to think that Nagel's juxtaposition of reasoning in the form modification of a belief about the direction one is driving in, because of its inconsistency with newly acquired evidence, with reasoning like Nagel's "I oppose the abolition of the inheritance tax... because I recognize that the design of property rights should be sensitive not only to autonomy but also to fairness..." is self-evidently ridiculous.  Says Brad:

"I do wonder: Does Gene Callahan have any idea what he has committed himself to when he endorses Thomas Nagel's claim that Nagel has transcendent direct access to truths of objective reality? I think not:

Thomas Nagel: [...my (HB's) ellipsis here, in place of a typo by Brad that repeated part of his own introduction, quoted above, to this quote...] I decide, when the sun rises on my right, that I must be driving north instead of south... because I recognize that my belief that I am driving south is inconsistent with that observation, together with what I know about the direction of rotation of the earth. I abandon the belief because I recognize that it could not be true.... I oppose the abolition of the inheritance tax... because I recognize that the design of property rights should be sensitive not only to autonomy but also to fairness...

Game, set, match, and tournament!"

That last sentence, which is Brad's, seems revealing of a mindset that sometimes creeps into his writing in his blog, less aimed at truth than at victory in some argumentative competition. I like a lot of what he does on his blog, but that attitude, and the related one that reads like an attempt to exhibit his hip and with-it-ness by using internet jargon that the unhip like me have to google ("self-pwnage", which Callahan is said to have committed), are not so appealing. The "transcendent direct access" I have already argued is mostly a straw-man of Brad's own creation, Nagel's point being primarily that (as says immediately following what Brad has quoted) "As the saying goes, I operate in the space of reasons." One aspect of operating in the space of reasons is trying to preserve some consistency between ones various beliefs; that seems to be the nub of the driving example (but we should not forget the important point that there is more than just deductive logic going on here... we have to decide which of the contradictory beliefs to give up). And we are also to some extent doing so (preserving consistency) in the case of the inheritance tax, though the full argument in this case is likely to be much more involved and less clear than in the case of the driving example. Nagel is arguing that we try to square our beliefs about the particular case of the inheritance tax with general beliefs that we (may) hold about how social institutions like property rights should be designed. Focusing on this consistency issue, though, can --- in both factual and ethical situations --- obscure the essential role of factors other than mere consistency in the process of reasoning about what beliefs to hold. As I mentioned in earlier posts, Nagel gives this somewhat short shrift, notably by not discussing inductive reasoning much, though he's clear about the fact that it's needed. But it's remarkable that DeLong---who I would guess shares Nagel's views on the inheritance tax, and possibly even his reasons (although he may also find some strength in arguments involving "social welfare functions) should think that this passage grounds an immediate declaration of victory. I guess it's because he wrongly thinks the issue is about "direct transcendent access".

Even more remarkable is philosopher Simon Blackburn's very similar reaction---if, as I am guessing, his example of "why income distribution in the US is unjust" is prompted in part by Nagel's reference to the inheritance tax. There are points I agree with in Blackburn's article, but then there is this:

According to Nagel, Darwinians can explain, say, why we dislike pain and seek to minimize bringing it about for ourselves and for others we love. But, Nagel thinks, for the Darwinian, its “real badness” can be no part of the explanation of why we are averse to it. So it is another mystery how real badness and other real normative properties enter our minds. Nagel here manifests his founding membership of a peculiar and fortunately local philosophical subculture that thrives by resolutely dismissing the resources of the alternative, Humean picture, which sees our judgement that pain is a bad thing as a useful expression of our natural aversion to it. All he says about this is that it “denies that value judgements can be true in their own right”, which he finds implausible. He is silent about why he thinks this, perhaps wisely, if only because nobody thinks that value judgements are true in their own right. The judgement that income distribution in the US is unjust, for instance, is not true in its own right. It is true in virtue of that fact that after decades of lobbying, chief executives of major companies earn several hundred times the income of their rank-and-file workers. It is true because of natural facts.

Parenthetically, but importantly: I agree with Blackburn's characterization of Nagel as believing that the "real badness"
of pain cannot be a main part of a Darwinian explanation of our aversion to pain. And I disagree with this belief of Nagel's.

However, I don't know what's so peculiar and local about resolutely dismissing (sometimes with plenty of discussion, though one virtue of Nagel's book is that it is short, so a point like this may not get extensive discussion) the Humean view here that this badness is just "natural aversion".  But in any case, Blackburn's discussion of his example is truly weird.  It seems reasonable to view a statement like "income distribution in the US is unjust" as true both because of the "natural facts" Blackburn cites, which explain how it has come to be what it is, and because of the component where the actual "values" come in, which give reasons for our belief that this high degree of inequality, is in fact unjust.  True, according to some theories of justice, e.g. a libertarian one, the genesis of a pattern of income and wealth distribution may be germane to whether or not it is just.  Blackburn might be adducing such an explanation, since he mentions "lobbying" as a cause (and not, say "hard work").  But if so, he still hasn't explained: what's wrong with lobbying?  Why does it cast doubt on the justice of the resulting outcome?  What Nagel means by value judgements being true "in their own right" is not likely that every statement with a value component, like Blackburn's about US income and wealth distribution, is true in and of itself and no reasons can be given for it.  What I think he means is that at some point, probably at many different points, there enters into our beliefs about matters of value an element of irreducible judgement that something is right or wrong, good or bad, and that this is objective, not just a matter of personal taste or "natural aversion".  What Blackburn's statement reads most like, due to his emphasis on "natural facts", is an attempt to substitute the causal factors leading to US income distribution being what it is, for the moral and political considerations---quite involved, perhaps subtle, and certainly contentious---that have led many to judge that it should not be what it is.  It's quite clear from Nagel's discussion of the inheritance tax what he thinks some of those considerations are: "autonomy and fairness". I just don't understand how someone could think that Blackburn's discussion of why US income distribution is unjust is better than an account in terms of concepts like autonomy and fairness---the sort of account that Nagel would obviously give. I've gotten some value from parts of Blackburn's work, even parts of this article, but this part---if this reading is correct---seems monumentally misguided.  Or does he think that the rest of the explanation is that human beings just have a "natural aversion" to income distribution that is as unequal, or perhaps as influenced by lobbying, as the US's currently is.  But you might think that a cursory look at a large part of the Republican party in the US would have disabused him of that notion.

Perhaps I'm being excessively snarky here...advocates, like Blackburn, of the natural aversion view would probably argue that it needs to be supplemented and modified by reasoning.... perhaps it is just that the "irreducibly moral", as opposed to the deductive/analogical reasoning component, of this process, is still just a matter of natural aversion.  I would think more Hobbesian considerations would come into play as well, but that is a matter for (you may be sorry to hear) another post.

Russell Blackford on Thomas Nagel on "objective values"

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Russell Blackford formulates what he thinks is Thomas Nagel's argument for "the existence of objective values".  I think I disagree with Blackford on this.  Blackford's point seems to be that although he doesn't want to die a premature death, or suffer horrible torture, it wouldn't really be bad if he did.  Or at least, that he is not logically committed to thinking it would be.  Perhaps the logical point is correct, I'm not sure.  I would have to figure out what the difference is between valuing something and thinking it is really valuable.  I'm kind of suspicious of this supposed difference, but I suppose it merits close thought.  (References, anyone?) How does it differ from the difference between thinking the cat is on the mat and thinking the cat is really on the mat?  True, there is the difference, in Blackford's formulation, between "valuing X" and "thinking X is valuable".  Is that the crucial bit of Blackford's argument?  Or, since we're concerned with practical reason here, is to state or think or that one values something just to state that or think that one will take action to bring it about, but not to make the "deontic" statement that it should come about?  (All subject to qualifications about other things being equal, or about how it should be traded off with other things valued, of course.)  But even if this distinction makes sense, which it may well do, I think Nagel would argue... and I would follow him... that most of us just DO not only value certain things, but think that those things really are valuable.

Nagel and Delong II: Fallibility and Transcendence

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In my first post on Brad Delong's series of criticisms of Thomas Nagel's new book Mind and Cosmos I focused not on Brad's initial critcism but on a later post that seemed to be implying Nagel put too much weight on "common sense".  In this post I'll focus on Brad's initial criticism, and in particular on what seems to me his misunderstanding of Nagel's arguments concerning reason, as crucially dependent on the notion that reason is infallible at least in some cases.

Brad's critique began with a reaction to some remarks by Tyler Cowen, in particular Cowen's assertion that "People will dismiss his [Nagel's] arguments to remain in their comfort zone, while temporarily forgetting he is smarter than they are and furthermore that many of their views do not make sense or cohere internally."

Now I think it is unfortunate that Cowen is speculating about who's "smarter than" who, and unfortunate that Brad joins him in doing so.  Everyone involved seems to be quite smart, but unfortunately Brad seems to me to be misunderstanding what the main thrust of Nagel's argument is, and where its main weakness lies.  DeLong reacts to Cowen:

And here Tyler appears to me to have gone off the rails. Thomas Nagel is not smarter than we are--in fact, he seems to me to be distinctly dumber than anybody who is running even an eight-bit virtual David Hume on his wetware.

He fixates on a single example taken from Nagel's book and, I think, fails to understand the role Nagel thinks this example plays. Brad seems to think it is crucial that Nagel view reason as infallible. "And my certainty that I know must be correct!" as he puts it in his gloss on Nagel:

Nagel's argument, to the extent that I understand it and that it is coherent, goes roughly like this:

Suppose we think we are going south-southwest and see the sun rising before us. We don't think: "the heuristics of reasoning that have evolved because they tend to boost reproductive fitness conclude that it is very likely that I am not in fact going south-southwest". We think, instead: "I know that the sun rises in front of me when I am going east! Either I am hallucinating, or I must be going roughly east! I deduce this by my reason, and my reason is a mechanism that can see that the algorithm it follows is truth-preserving! My mind is in immediate contact with the rational order of the universe! I don't just think I am going east! I know I am either hallucinating or going east! And my certainty that I know must be correct! And I know that my certainty must be correct--and that triumph of reason cannot be given a purely physical explanation! Since I believe I am not hallucinating, I abandon the belief that I am going south-southwest because of my reason's transcendent grasp of objective reality! My consciousness is an instrument of transcendence that grasps objective reality! And no blind evolutionary process can produce such a transcendent instrument!"

Aspects of this example of Nagel's bothered me as well, but it plays a much less central part in Nagel's book than you might think from Brad's gloss. Note that even the material in quotes is a gloss, not a quote from Nagel, although it draws fairly heavily on him. (Further down in this post, I quote the passage in Nagel from the first appearance of the example to the last explicit reference to it.  Brad's post also contains further material on the general topic of reason directly quoted from Nagel.)  In the context of Brad's post, the term "Nagel's argument" seems to imply that this is the main argument of the book, on which it stands or falls.

As I said, I don't think the example is central. Rather, it is intended as an example of something central to the book, which is the claim that reason has the power --- imperfect and fallible, to be sure --- to get us in touch with objective reality, in a way that helps us transcend the appearance of things from our own particular viewpoint or perspective. It is probably also intended as part of a discussion of how logic --- the avoidance of contradiction --- is an essential part of our ability to engage in more subtle and substantive forms of reasoning. I will discuss this second point later, concentrating for the moment on the first.

Nagel is extremely clear that he does not believe that reason's power to help get us in touch with objective reality is infallible. (See the next quote I display from Nagel for an utterly explicit statement of this.)  It may seem that he is claiming it to be infallible in driving example, but even if he is, that does not seem crucial to his main line of argument. Most of Brad's ridicule of Nagel's argument is directed against the claim of infallibility, so it just misses its target if by "Nagel's argument" is meant, as is clear from the context, the overall line of argument of Nagel's book.

The overall argument of the book is not a single line of reasoning. But some main strands concern the nature and origin of life, of consciousness, and---what is under discussion here----of reason. Here is how Nagel puts his main argument concerning the nature of reason:

Thought and reasoning are correct or incorrect in virtue of something independent of the thinker's beliefs, and even independent of the community of thinkers to which he belongs. We take ourselves to have the capacity to form true beliefs about the world around us, about the timeless domains of logic and mathematics, and about the right thing to do. We don't take these capacities to be infallible, but we think they are often reliable, in an objective sense, and that they can give us knowledge. [Mind and Cosmos, pp. 80-81]

Perhaps some confusion has arisen because of Nagel's use of the word "reliable" elsewhere in the book (e.g. in the excerpt DeLong quotes)...it should not be taken to imply infallibility. In Brad's favor, the "directness" with which Nagel says reason "puts us in touch with the rational order of things" in this particular example, is thought by Nagel to strengthen his case. I just don't think it's the main point.

Lest anyone misunderstand, I don't agree with Nagel that our understanding of reason as part of a process enabling us to --- fallibly, Nagel admits, and partially, I might add --- get in touch with an objective reality that transcends each of our particular perspectives on it, provides support to the view that reason could not have evolved through natural selection.

Brad goes on to propose a counterexample to the claim that the bit of reasoning in Nagel's example is infallible. It is that "During northern hemisphere winter, if you are near the North Pole, it is perfectly possible to see the sun rise due south if you are due solar north of the center of the earth as you come out of the Earth's shadow. And I was. And I did."

Several things can be said about this. The most important one is that Nagel need not and does not claim infallibility. Less important is that Nagel explicitly described his example as one in which "I am driving...". Brad was flying. So Brad's "it happened to me" is not literally true. Moreover the distinction between flying and driving is not an irrelevant one (like that between its being Nagel or DeLong who is doing the reasoning...) but one that is probably relevant. I don't know whether there are any roads near enough the north pole that one could, driving, have the experience Brad did. Perhaps there is land, or at certain times of the year, perhaps there is still enough sea ice, near enough the pole that one could do this off-road, by driving a long way off-road, or bringing a vehicle in by air. Or perhaps not. I really don't think it matters much. There are some background assumptions that are not made explicit, though suggested by the framing of the situation, as there are in most pieces of reasoning.

Here's Nagel's introduction of the example, and its sequel:

But suppose I observe a contradiction among my beliefs and "see" that I must give up at least one of them. (I am driving south in the early morning and the sun rises on my right.) In that case, I see that the contradictory beliefs cannot all be true, and I see it simply because it is the case. I grasp it directly. It is not adequate to say that, faced with a contradiction, I feel the urgent need to alter my beliefs to escape it, which is explained by the fact that avoiding contradictions, like avoiding snakes and precipices, was fitness-enhancing for my ancestors. That would be an indirect explanation of how the impossibility of the contradiction explains my belief that it cannot be true. But even if some of our ancestors were prey to mere logical phobias and instincts, we have gone beyond that: We reject a contradiction just because we see that it is impossible, and we accept a logical entailment just because we see that it is necessarily true.

In ordinary perception, we are like mechanisms governed by a (roughly) truth-preserving algorithm. But when we reason, we are like a mechanism that can see that the algorithm it follows is truth-preserving. Something has happened that has gotten our minds into immediate contact with the rational order of the world, or at least with the basic elements of that order, which can in turn be used to reach a great deal more. That enables us to possess concepts that display the compatibility or incompatibility of particular beliefs with general hypotheses. We have to start by regarding our prereflective impressions as a partial and perspectival view of the world, but we are then able to use reason and imagination to construct candidates for a larger conception that can contain and account fo that part. This applies in the domain of value as well as of fact. The process is highly fallible, but it could not even be attempted without this hard core of self-evidence, on which all less certain reasoning depends. In the criticism and correction of reasoning, the final court of appeal is always reason itself.

What this means is that if we hope to include the human mind in the natural order, we have to explain not only consciousness as it enters into perception, emotion, desire, and aversion but also the conscious control of belief and conduct in response to the awareness of reasons---the avoidance of inconsistency, the subsumption of particular cases under general principles, the confirmation or disconfirmation of general principles by particular observations, and so forth. This is what it is to allow oneself to be guided by the objective truth rather than just by one's impressions. It is a kind of freedom---the freedom that reflective consciousness gives us from the rule of innate perceptual and motivational dispositions together with conditioning. Rational creatures can step back from these influences and try to make up their own minds. I set aside the question whether this kind of freedom is compatible or incompatible with causal determinism, but it does seem to be something that cannot be given a purely physical analysis and therefore, like the more passive forms of consciousness, cannot be given a purely physical explanation either.

If I decide, when the sun rises on my right, that I must be driving north instead of south, it is because I recognize that my belief that I am driving south is inconsistent with that observation, together with what I know about the direction of rotation of the earth. I abandon the belief because I recognize that it couldn't be true. If I put money into a retirement account because the future income it generates will be more valuable to me than what I could spend it on now, I act because I see that this makes it a good thing to do. If I oppose the abolition of the inheritance tax, it is because I recognize that the design of property rights should be sensitive not only to autonomy but also to fairness. As the saying goes, I operate in the space of reasons.[Mind and Cosmos, pp. 91-92]

Gene Callahan criticizes Brad as follows:

So Nagel gives us two beliefs:
1) The sun rises in the east (where I am); and
2) I am driving south, which means the east will be on my left.
And a fact: But the sun is rising to my right!

So Nagel's point is that we cannot continue to hold 1) and 2) simultaneously: "I must give up at least one of them." How could he have said that more plainly?

Then Nagel goes on to state that "IF" (notice, that "if" is right in the original text, I did not add it!) he decides to give up belief 2), it will be because he sees he cannot logically hold 1) and 2) at the same time. Notice what the "if" implies: Nagel clearly understands that he has the option of giving up belief 1) instead! Otherwise, no point to the "if."

Now, Brad Delong comes along and says, "What an idiot! [And he really does insult Nagel like that.] Once, I was in that situation, and I had to give up belief 1)!"

Ahem. One does not disprove the proposition that one ought to give up at least one of two contradictory beliefs by showing how once, one gave up one of two contradictory beliefs.

Brad's response:

Nagel does not believe: "the sun rises in the east (where I am)." Nagel believes: "the sun rises on my right".

Thus the two beliefs that Nagel's reason tells him are in conflict are (a) his belief that he is going south, and (b) his belief he sees the sun rising on his right. The choice he gives himself is between concluding that he is going north and concludeingthat he is hallucinating.

Now I understand that Callahan wishes that Nagel were not Nagel but rather some Nagel' who had added a third belief: (c) "I am in a normal place (but there are weird places on earth where the sun rises in a non-standard way)."

But we go to argument with the Nagel we have, and not the Nagel' Callahan wishes we had.

Callahan would presumably say that Nagel was just being sloppy, and that there is actually an unsloppy Nagel' who had made the argument that Callahan wishes he had made, and whose reason does have transcendental access to objective reality, and that we should deal with the argument not of Nagel but of Nagel'.

But Callahan's confusion of the Nagel' he wishes we were talking about with the Nagel who we are talking about demonstrates my big point quite effectively: powerful evidence that Nagel is a jumped-up monkey using wetware evolved to advance his reproductive fitness, rather than a winged angelic reasoning being with transcendental access to objective reality. No?

I think Callahan is roughly right here. Roughly because it's not obviously correct that "Nagel gives us two beliefs". Callahan's (2) is stated in Nagel's parenthetical introduction of the example (see the quote above). But the parenthetical introduction is probably best read as describing the situation, not explicitly attributing beliefs ("I am driving south", not "I believe I am driving south"). It's clear we're to take as implicit that the subject of the example believes this, though, and when Nagel returns to the example later in the passage I quoted it is made explicit: this is the belief that is given up. That return to the example also makes it clear that there are background beliefs not initially mentioned in Nagel's parenthetical introduction of the example: Nagel mentions "what I know about the direction of rotation of the earth". This is presumably where Callahan gets number (2) namely "The sun rises in the east (where I am)." That seems a correct reading of Nagel, so DeLong's "Nagel does not believe: "the sun rises in the east (where I am)." Nagel believes: "the sun rises on my right"." just seems wrong.  The Nagel of the example believes both of these things (if we understand "the sun rises on my right" to mean something like "the sun is rising on my right".  Brad's misinterpretation is probably based on taking the parenthetical sentence introducing the example as a statement of the two beliefs that are in contradiction, rather than a sketch of a situation in which "I observe a contradiction in my beliefs". (Brad also changes Nagel's "driving south" to "going south", which affects, as I discussed above, whether Brad's flying experience is relevant.)

I think Nagel is getting at several things with this example, in light of the surrounding discussion.

(1) One is the idea that deductive reason helps us access truths about the world that go beyond our own particular perspective on it, because the avoidance of inconsistency is integral to the use of language, which in turn enables us to describe how the world is or might be from a point of view that is not just the perspective of one being that it makes possible. I am not sure what Brad means by "transcendent access" to objective reality--- it may just be a rhetorical flourish, liked "winged" and "angelic". The term "transcendent access" does not appear in Mind and Cosmos. When Nagel uses words with the root "transcend", he is referring to transcending a limited point of view to come up with a view of the world "as it is independently of the thinker's beliefs and even independently of the community of thinkers to which he belongs." (He also uses it---probably in the same sense---to refer to "a transcendent being", a notion he finds unappealing.) In his description of "what it is to be guided by the objective truth" toward the end of the long quote above, he is quite clear that this involves observations and (broadly speaking) "inductive" reasoning ("confirmation and disconfirmation"), and earlier he mentions "imagination" in addition to reasoning. (So if Brad's "Humean heuristics" just means inductive reasoning broadly construed, then it looks like Nagel's on board with it.) When reading the discussion of the driving example in Mind and Cosmos and related passages in The Last Word, I have sometimes felt puzzled about why Nagel seems to be laying such emphasis on deductive reasoning. And in general, I'm slightly frustrated by the relative lack of discussion of induction or related non-inductive aspects of scientific reasoning in Nagel's writings. But I think the quoted passages make clear that for Nagel, reason comprises induction too. I think the reason for his stress on deduction and consistency is the importance --- as Nagel sees it --- of language, and language's intimate link with logic --- to the very formulation of theories and hypotheses, scientific and otherwise. Nagel's emphasis on "directness" in simple cases may or may not be misplaced, but I don't think it's the linchpin of his broader argument.

(2) Secondly, and perhaps more controversially, Nagel believes that we must conceive of our reasoning as autonomous and free---that we cannot view it as a mere disposition. A mere disposition is how Hume, on one reading, viewed "induction", if not deduction... here I think Nagel would disagree with Hume, and perhaps with DeLong, if "mere disposition" is what DeLong means by "Humean heuristics". The key point, for Nagel, is that "In the criticism and correction of reasoning, the final court of appeal is always reason itself." The theory of evolution itself is part of that objective picture of reality, transcending our individual perspectives on it, that reason enables us to arrive at. For Nagel, it would be absurd to let a belief in evolution by natural selection undermine our view that our reasoning, in conjunction with imagination and observation, can get us in touch with and is getting us in touch with objective reality, because our very belief in evolution itself relies on this view. It is this, and not infallibility or "transcendent access" (a term Nagel never uses) that is the most important, and that I think is crucial to his broader argument.  Note that this does not automatically imply that a belief in evolution by natural selection cannot modify our assessment of our reasoning, perhaps leading us to view particular judgments or modes of reasoning as suspect, because arising from heuristics that we can see to be reliable only in certain situations similar to those in which they evolved.  Indeed, Nagel seems overly impressed with this possibility---one of his main grounds for rejection of the notion that there could be an evolutionary-biological explanation of the advent of reason in humans is his view that such an explanation would necessarily undermine our assessment that the reasoning we exercise in conjunction with our other faculties actually is, on balance, tending to get us in touch with objective reality.

Brad does address some of these issues, in response to Callahan's pointing out that they are the main ones; I will take up that part of their discussion in a later post.

Let me here take up an element of the quoted passage from Nagel that is bound to have raised some hackles.
Nagel: "I set aside the question whether this kind of freedom [to decide what to believe and how to act for reasons, i.e. by reasoning -- HB] is compatible or incompatible with causal determinism, but it does seem to be something that cannot be given a purely physical analysis and therefore, like the more passive forms of consciousness, cannot be given a purely physical explanation either."

This really is a key argument for Nagel. However, in my view, it needs to be understood in terms of the subtleties of emergence. As I have written elsewhere, I think there is some crucial unclarity in Nagel (or in my understanding of him) about what "purely physical explanation" might mean. If it means "explanation in terms of the concepts of physics" then I suspect that the hypothesis that "this kind of freedom [...] cannot be given a purely physical explanation [...]" is correct.  (However, I think I still have a substantive disagreement with Nagel on the meaning of "explanation".)   But if we allow an evolutionary biological evolution to use concepts like "reason" (which seems rather reasonable if one is going to try to explain the origin of our ability to reason), it seems to me that this is compatible with our eventually having an evolutionary-biological explanation of its historical origin. Here also I think I disagree with Nagel, who sometimes refers to "physics extended to include biology", suggesting that to him an evolutionary-biological explanation is a kind of purely physical explanation. I've discussed this some in my first post on Mind and Cosmos, and will discuss it more in future posts. There are deep and subtle philosophical and scientific questions involved, but in my view it is here if anywhere that Nagel goes importantly astray in dealing with reason, and not primarily in some actual or putative attribution of infallibility to simple judgements of contradiction, nor even in the notion (which Nagel does appear to subscribe to, but which I'm not sure I want to endorse) that the faculty of avoiding contradiction involves our minds being in "immediate contact with the rational order of things" [Mind and Cosmos, p. 91].

 

 

Nagel and DeLong I: Common Sense

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Brad DeLong has been hammering --- perhaps even bashing --- away at Thomas Nagel's new book Mind and Cosmos (Oxford, 2012).  Here's a link to his latest blow. I think Nagel's wrong on several key points in that book, but I think Brad is giving people a misleading picture of Nagel's arguments.  This matters because Nagel has made very important points --- some of which are repeated in this book, though more thoroughly covered in his earlier The Last Word (Oxford, 1997) --- about the nature of reason, defending the possibility of achieving, in part through the use of reason, objectively correct knowledge (if that is the right word) in areas other than science, and giving us some valuable ideas about how this can work in particular cases, for example, in the case of ethics, in The Possibility of Altruism [Princeton, 1979].

In his latest salvo Brad suggests that "If you are going to reject any branch of science on the grounds that it flies in the face of common sense, require[s] us to subordinate the incredulity of common sense, is not based ultimately on common sense, or is a heroic triumph of ideological theory over common sense--quantum mechanics is definitely the place to start…".  This is preceded by some quotes from Nagel:

  • But it seems to me that, as it is usually presented, the current orthodoxy about the cosmic order is the product of governing assumptions that are unsupported, and that it flies in the face of common sense…
  • My skepticism is… just a belief that the available scientific evidence, in spite of the consensus of scientific opinion, does not… rationally require us to subordinate the incredulity of common sense…
  • Everything we believe, even the most far-reaching cosmological theories, has to be based ultimately on common sense, and on what is plainly undeniable…
  • I have argued patiently against the prevailing form of naturalism, a reductive materialism that purports to capture life and mind through its neo-Darwinian extension…. I find this view antecedently unbelievable— a heroic triumph of ideological theory over common sense…

Now there are things I disagree with here, but Nagel is clearly not claiming that no theory that is not itself a piece of common sense is acceptable. Indeed, the second bullet point makes it clear that he allows for the possibility that scientific evidence could "rationally require" him to subordinate the incredulity of common sense. It is his judgment that it does not in this case. Now---at least with regard to the possibility of an explanation by evolutionary biology of the emergence of life, consciousness, and reason on our planet and in our species, which is what I think is at issue--- I don't share his incredulity, and I also suspect that I would weigh the scientific evidence much more heavily against such incredulity, if I did share some of it.  But Nagel is not commited to a blanket policy of "reject[ing] scientific theories because they fail to match up to your common sense." Regarding the third bullet point, it's perhaps stated in too-strong terms, but it's far from a claim that every scientific theory can directly be compared to common sense and judged on that basis. The claim that scientific theories are "ultimately based in common sense and on what is plainly undeniable" does not imply that this basis must be plain and direct. Logic and mathematics develop out of common-sense roots, counting and speaking and such... science develops to explain "plainly undeniable" results of experiments, accounts of which are given in terms of macroscopic objects... Some of this smacks a bit too much of notions that may have proved problematic for positivism ("plainly undeniable" observation reports?)... but the point is that common sense carries some weight and indeed is a crucial element of our scientific activities, not that whatever aspect of "common sense" finds quantum theory hard to deal with must outweigh the enormous weight of scientific experience and engineering practice, also rooted "ultimately" according to Nagel in common sense, in favor of that theory.

Just for the record I don't find that the bare instrumentalist version of quantum theory as an account of the probabilities of experimental results "flies in the face of common sense" --- but it does seem that it might create serious difficulty for the conception of physical reality existing independent of our interactions with it. At any rate it does not seem to provide us with a picture of that sort of physical reality (unless you accept the Bohm or Everett interpretations), despite what one might have hoped for from a formalism that is used to describe the behavior of what we tend to think of as the basic constituents of physical reality, the various elementary particles or better, quantum fields.  But if someone, say Nagel, did believe that this all flies in the face of common sense, it would be open to him to say that in this case, we are permitted, encourage, or perhaps even required to fly in said face by the weight of scientific evidence.

As I've said, I disagree on two counts with Nagel's skepticism about an evolutionary explanation of mind and reason: it doesn't fly in the face of my common sense, and I weigh the evidence as favoring it more strongly than does Nagel. Part of my disagreement may be that what Nagel has in mind is an evolutionary explanation that is commited to a "reductive materialism that purports to capture life and mind through its neo-Darwinian extension." Whereas I have in mind a less reductive approach, in which consciousness and reason are evolutionarily favored because they have survival value, but we do not necessarily reduce these concepts themselves to physical terms. In my view, biology is rife with concepts that are not physical, nor likely to be usefully reduced to physical terms--- like, say, "eye". As with "eye", there may be no useful reduction of "consciousness" or "perception" or "thought" or "word" or "proposition", etc.., to physics, but I don't think that implies that the appearance of such things cannot have an evolutionary explanation. (Nor, just to be clear, does it imply that these things are not realized in physical processes.) So I might share Nagel's incredulity that such things could have a "materialist" explanation, if by this he means one in terms of physics, but not his incredulity about evolutionary explanations of the appearance of mind and reason. To me, it seems quite credible that these phenomena form part of the mental aspect of structures made of physical stuff, though we will never have full explanations for all the phenomena of consciousness and the doings of reason, in terms of this physical structure.

(David Deutsch's recent book The Beginning of Infinity is one excellent source for understanding such non-reductionism---see in particular its Chapter 5, "The Reality of Abstractions".)

I'll likely make several more posts on this business, both on other ways in which I think Brad and others have mischaracterized Nagel's arguments or misplaced the emphasis in their criticisms, and on why this matters because some important points that Nagel has made on matters closely related to these, that I think have value, are in danger of being obscured, caricatured, or dismissed under the influence of the present discussion by Brad and others.

My short review of David Deutsch's "The Beginning of Infinity" in Physics Today

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Here is a link to my short review of David Deutsch's book The Beginning of Infinity, in Physics Today, the monthly magazine for members of the American Physical Society.  I had much more to say about the book, which is particularly ill-suited to a short-format review like those in Physics Today.  (The title is suggestive; and a reasonable alternative would have been "Life, the Universe, and Everything.")   It was an interesting exercise to boil it down to this length, which was already longer than their ideal.  I may say some of it in a blog post later.

It was also interesting to have such extensive input from editors.  Mostly this improved things, but in a couple of cases (not helped by my internet failing just as the for-publication version had been produced) the result was not good.  In particular, the beginning of the second-to-last paragraph, which reads "For some of Deutsch’s concerns, prematurity is irrelevant. But fallibilism undermines some of his claims ... " is not as I'd wanted.  I'd had "this" in place of "prematurity" and "it" in place of "fallibilism".  I'd wanted, in both cases, to refer in general to the immediately preceding discussion, more broadly than just to "prematurity" in one case and "fallibilism" in the other.  It seems the editors felt uncomfortable with a pronoun whose antecedent was not extremely specific.  I'd have to go back to notes to see what I ultimately agreed to, but definitely not plain "prematurity".

One other thing I should perhaps point out is that when I wrote:

Deutsch’s view that objective correctness is possible in areas outside science is appealing. And his suggestion that Popperian explanation underwrites that possibility is intriguing, but may overemphasize the importance of explanations as opposed to other exercises of reason. A broader, more balanced perspective may be found in the writings of Roger Scruton, Thomas Nagel, and others.

I was referring to a broader perspective on the role of reason in arriving at objectively correct views in areas outside science. "More balanced" was another editorial addition, in this case one that I acquiesced in, but perhaps I should not have as some of its possible connotations are more negative than I intended.  "Appealing," though not an editorial edition, is somewhat off from what I intended.  I wanted also to include suggestion of "probably correct" since something can be appealing but wrong, but couldn't find the right word.  I shortened this discussion for reasons of space, but I had initially cited Scruton specifically for aesthetics, and recommended his "On Beauty", "Art and the Imagination", and "The Aesthetics of Architecture".  I haven't read much of his work on politics (he is a conservative, although from what I have read a relatively sensible one at the philosophical level) nor his "Sexual Desire", so don't mean to endorse them.  Likewise I had initially recommended specifically Nagel's "The View from Nowhere" and "The Last Word", and was not aware of his recent "Mind and Cosmos"; I emphatically did not mean to endorse his skepticism, in that book, about evolutionary explanations of the origins of life and mind, although I do think there is much of interest in that book, and some (but certainly not all!) of the criticism of it that I've seen on the web is misguided.  I am much more in sympathy with Deutsch's views on reductionism than with Nagel's:  both are skeptical about the prospects for a thoroughoing reduction of mind, reason, and consciousness to physical terms, but Nagel, bafflingly, seems to think that an evolutionary explanation of such phenomena is tantamount to such physical reductionism.  Deutsch seems to me more sophisticated about the nature of actual science, and how non-reductionist many scientific explanations are, and about how that can nevertheless be compatible with physical law.  I should say, though, that I am less sympathetic than Deutsch is to accounts of mind and consciousness as being essentially a computer running a certain kind of program.  I view embodiment, interaction with a sufficiently rich environment, and probably a difficulty in disentangling "hardware" and "software" (perhaps related to Douglas Hofstadter's notion of "strange loops") as likely to be crucial elements of an understanding of mind and consciousness.  Of course it may be that with a sufficiently loose notion of "kind of computer program" and "kind of input" some of this could be understood in the computational terms Deutsch seeks.