To me objectivity is the simplest reliable consensus model. "Simplest" is important here because I think it leaves no reason for us to entertain unknowable "things in themselves". There may be unknowable aspects of things, but if so, there's no reason to suppose any guesses we make about them will be accurate. So saying they *might* exist seems to do no work.
The whole notion of unknowable reality feels like a device to preserve cherished notions, to continue holding that they're true despite the lack of evidence. And it seems like this goes all the way back to Kant. I found these points in the SEP entry on Kant pretty interesting.
"The problem is that to some it seemed unclear whether progress would in fact ensue if reason enjoyed full sovereignty over traditional authorities; or whether unaided reasoning would instead lead straight to materialism, fatalism, atheism, skepticism (Bxxxiv), or even libertinism and authoritarianism (8:146). "
"Yet the original inspiration for the Enlightenment was the new physics, which was mechanistic. If nature is entirely governed by mechanistic, causal laws, then it may seem that there is no room for freedom, a soul, or anything but matter in motion. This threatened the traditional view that morality requires freedom. We must be free in order to choose what is right over what is wrong, because otherwise we cannot be held responsible. It also threatened the traditional religious belief in a soul that can survive death or be resurrected in an afterlife. So modern science, the pride of the Enlightenment, the source of its optimism about the powers of human reason, threatened to undermine traditional moral and religious beliefs that free rational thought was expected to support. This was the main intellectual crisis of the Enlightenment.
The Critique of Pure Reason is Kant’s response to this crisis."
Personally, I think Kant's mistake, and the mistake many philosophers make, is in trying to find a way to preserve the original naive versions of these concepts, rather than facing the music and scrutinizing them. Of course that's coming from a philistine who thinks the mechanistic stance is the way to go. Granted, sometimes a purely mechanistic explanation isn't available in science, but history seems to indicate we'll get one if we just be patient. It isn't always a comforting view. Although if we understand the mechanics of reality sufficiently, we can hope to make our own comfort.
But always interested in any arguments showing these views may be wrong.
Thanks for those SEP extracts. Freedom is something I didn't have the space to get into, but I think that's an area where the difference between the modern view and the ancient one comes into even sharper focus. Nagel has a section on freedom and autonomy as well which I just started reading last night, and it reminds me of just how much the idea of freedom has changed and has become such an intractable battle between the the subjective sense that we have free choice and responsibility as opposed to the objective sense that we don't. The problem all but disappears with ancient virtue ethics, though. Freedom wasn't about the ability to make choices. Who cares about being able to choose if you don't know what the best choice is? For them, freedom is knowledge. Their ethics might be called vague and somewhat lawless (which Kant would not have liked), but I think that view makes more sense than anything.
You could say Kant really drew a line in the sand between religion and reason. I want to say it's in the antinomies where he argues that you can't know whether the soul or God or freedom exist or don't exist. These are matters of faith, not reason. He imagined he was saving both, but I don't think he did anything for religious belief. His ethical system was a noble attempt to save autonomy, but I can't think of anyone who buys into the categorical imperative (because Nazis).
The problem with science right now, in my opinion, is that it's not clear the mechanistic framework can in principle explain what needs to be explained. I was watching a debate on the afterlife in which Sean Carroll (I think that's who it was) argued in the same way, that the answers are coming. But you can always say the answers are in the future. These questions have been around for centuries and I don't see even the beginnings of an answer, which makes me think it doesn't seem likely a mechanistic understanding can accommodate the fullest reality. Don't get me wrong, I don't want naive concepts either, and I'm certainly not committed to certain religious beliefs like the immortality of the soul and the like, but I don't think saying subjective experience is not illusory is naive. That said, I'd be perfectly happy with science doing what science does so long as certain prominent figures stop claiming science has everything in place to figure these things out (cough, cough...Sean Carroll...cough) someday.
I meant to say that since you seem to be very much in the know when it comes to what counts as scientific these days, it's nice to hear the "simplest consensus model", or at least some form of consensus, is not something that's seen as an affront to what science is trying to do. I really wasn't sure how views about consensus-as-objectivity would go over, as that's how I see it too. (I remember a physics professor throwing a hissy fit when we were discussing instrumentalism.)
Also—totally irrelevant—I saw that the Nagel book is ranked #22 on Amazon for "German Language Instruction", which reminded me of our conversation about that and made me laugh.
I hadn't heard that about ancient attitudes toward free will. Interesting. And it's closer to my own compatibilist conception of having the capacity for forethought. A lot of the contemporary debate seems tangled up with theology and the idea of a judgment day. Some ancient societies seemed concerned about that (some periods in Egypt for instance), but not all. But it also gets to something I'm increasingly on the watch for: projecting our own contemporary issues onto what people wrote millenia ago. It seems like getting into the details often makes that dicey.
My attitude toward moral theories is that none of them should be adopted dogmatically, none of them are "true" in that sense, but many of them have pragmatic use. So for many potential situations, the categorical imperative, basically can we be consistent about it, can be useful, just not in any absolute sense where we have to tell the truth to the Gestapo about the refugees we're hiding.
Carroll was in a debate about the afterlife? I would imagine he repeated one of his favorite points, that we have a complete understanding of everyday physics, which doesn't leave much room for any non-physical stuff. I think he's right, although people tend to overinterpret that, that because we have that understanding, we also understand all the mechanisms built on top of it, which we definitely don't. My only unease with his usual presentation is it seems to rule out unknown unknowns, which I think we always have to admit are a thing.
It's often not clear how to explain things mechanistically. Quantum mechanics remains the one people think defies the mechanistic philosophy, although there are interpretations that preserve it. But another big one people talk about, consciousness, I think gets dissolved once we accept that our inner sense is just as fallible as the outer ones. It doesn't mean consciousness doesn't exist, but it does mean it isn't what we tend to intuitively assume it is.
Instrumentalism isn't popular among scientists. It's hard to be motivated to do the often difficult (sometimes dangerous) data gathering if you don't see yourself as in pursuit of truth. Although there are more instrumentalist scientists than is often assumed, but typically among theorists than experimentalists. Myself, I remain in the structural realist column, although a lot depends on what we mean by "real". In the end, "real" seems like the model we expect all the other "real" models to reconcile with.
Amazon is funny. I wonder why they struggle so much with categorizing philosophy. Is it that hard a category to understand? But I guess Politics and Social Sciences is better than the Spirituality section my local B&N puts them in (at least the time I went there, which is several years ago at this point).
I tend to take Aristotle as the key figure when I talk about ancient morality, but of course there are differences amongst them. I think comparing him to Kant reveals the split between ancient and modern ethics most clearly. For the ancients, morality wasn't about free will. It's not clear whether this was even a problem (in our sense) in Homer. Nature was simply taken as given—clearly there are things you can't change and things that make you who you are, for better or worse. What matters most for Aristotle is happiness, which he takes to be the highest good for us. Kant, on the other hand, is explicit in saying we should not take happiness into consideration. One of the most interesting things about Aristotle's view is that virtue, or excellence of character, comes about by habit. You are what you habitually do. There are certain things you can't help about who you are, but this doesn't mean you can't live whatever the good life means for you. Each of us has to strive to find what moderation means for us. For instance, if I start eating like an Olympic athlete, that won't be good for me because I don't burn that many calories (seeing as I tend to prefer sitting on my lazy butt in front of the computer as I am now). The good life isn't about the freedom to choose or escaping nature. It's about knowing what to do within the confines of nature, especially one's own. Whatever your background or limitations, you can and should strive to be the sort of person who knows how to assess various situations appropriately for you. Which means—contrary to Kant—there can't be rules of conduct:
"But this must be agreed upon beforehand, that the whole account of matters of conduct must be given in outline and not precisely, as we said at the very beginning that the accounts we demand must be in accordance with the subject-matter; matters concerned with conduct and questions of what is good for us have no fixity, any more than matters of health. The general account being of this nature, the account of particular cases is yet more lacking in exactness; for they do not fall under any art or precept but the agents themselves must in each case consider what is appropriate to the occasion, as happens also in the art of medicine or of navigation."
I imagine many people today actually believe what Aristotle says about morality without knowing a thing about him. His views seem fairly sophisticated in many ways. Even the concept that you are what you do, I imagine that advice is all over the place in our self-help books (I don't read self-help books, but I get a sense of what they're like from the subtitles on their covers.)
Here's part of the Sean Carroll debate. I can't find the whole thing:
I think for me at least it's less about what Carroll says and more about his smug, know it all demeanor. But I'm not too keen on what he says either.
"Quantum mechanics remains the one people think defies the mechanistic philosophy, although there are interpretations that preserve it."
I forget how Chalmers puts it, but I liked what he said about those who try to tie consciousness to quantum mechanics. He boils down their arguments to something like, consciousness is weird, QM is weird, so they must be connected.
"once we accept that our inner sense is just as fallible as the outer ones" It sounds like you're a hardcore skeptic, then!
Yeah, I can understand why those who do the grueling lab work that makes up a great deal of science might not like to be told they're not discovering the nature of reality. It makes sense that the more theoretical and philosophical scientists would be more amenable to instrumentalism.
Amazon, I think, is just a total mess. Actually, I think it's becoming harder and harder to search the internet for things. It seems like a bunch of irrelevant junk is the first stuff to pop up. The B&N thing is so funny and sad at the same time. I've seen that weird categorization in other bookstores as well, back when there were bookstores. Americans know so little about philosophy that they think it makes sense to put philosophy in the "metaphysical" (woo woo crystals) section.
The impression I get of Aristotle is he didn’t have the hangups later writers did due to centuries of monotheism. His approach definitely seemed like a sort of self help, rather than trying to establish some abstract notions of “right” and “wrong”. I wonder what he would have thought of the modern moral realist vs antirealist debates.
Thanks for the debate link. Looks like it was a while ago, closer to the New Atheism period. I think Carroll’s presentation has softened somewhat over the years, probably due to age more than anything. Not that non-physicalists are any happier with him.
On quantum mechanics and consciousness, yeah. On the one hand, it’s easy to see why people go there. I think it crosses the mind of anyone learning about the measurement problem for the first time. And scientists themselves toyed with the idea in the early decades of quantum theory. But it’s the allure of the unknowable reality and what can be tucked away in it that I think makes at least some people passionate about it.
On consciousness, I am a skeptic, but only toward a theory of consciousness as something fundamental, unanalyzable, and inaccessible to third party observation. I do think consciousness is extremely *difficult* to analyze and observe objectively. A nuanced distinction, but one that means the difference between an impossible problem and an array of scientifically tractable ones.
I’ve never found Amazon particularly easy to peruse, although I can usually find things if I already know what I’m looking for. But yeah, there’s a growing sentiment that Google searches are getting worse. I remember search engines before Google, which were pretty useless because they sold the highest results. Google at least labels their sold spots, but I feel like I need to scroll past that junk to get to the real stuff. But I wonder if Google has started slipping in the endless arms race between them and the SEO optimizers.
Yeah, I've been bugged by Google Search for a few years now. Obviously, I'm not alone in that. Besides all the SEO stuff, I've wondered if the interweb has just gotten too big and too polluted with noise for effective searching. Searches for answers turn up more people guessing than knowing. Tragedy of the Commons!
Nagel is defending realism within the larger purpose of the book. He is trying to establish the possibility, not to say the credibility, of an objective viewpoint for beings whose subjectivity is inescapable. Inevitably, this leads him into Kantian questions about whether knowledge of reality in itself is possible. Here he opts for a weak rather than a strong realism, as you've noted. His position is that while reality is unknowable, it must be true that either our conception has something to do with it, or nothing at all to do with it; and he sees no special reason to assume the latter. On the contrary, it seems more reasonable to him that we should suppose our conception has some relation to reality, even though technically it may be unknowable. It's not an especially defensible position, but as far as he's concerned, neither is its opposite, taken absolutely; and if he has to choose, he would lean towards the more common-sense view.
The whole discussion is to one side of his main thesis. His reasons for contemplating the unknowability of reality are not Kant's, as far as I can tell. You have a much better command of the epistemological tradition than I do, so I'm treading cautiously here, but Kant's reasons seem to have to do with the limits imposed on us by certain mental structures required to make sense of the appearances: structures such as space, time, and I guess causality, beyond which (as you've very effectively illustrated) our thoughts simply cannot go.
Nagels' reasons are different. They have to do with the fact of our subjectivity, which we can never escape to get a truly objective view. It is this, not the limitation on our abstract conceptions, that makes objective knowledge impossible in principle. I think Nagel largely concedes the abstract limitations, but he doesn't accept them as conclusive, in the weakly realist sense I've described. His own puzzle stands largely outside the tradition; or rather, in the less popular part of the tradition where we find Leibniz, the part that grants a genuine place to subjectivity. While defending realism in a sideways fashion against the Kantian tradition, his problem is how to maintain it once we accept the inescapability of the subjective viewpoint. The solution seems to involve both an asymptotic conception of the objective view, as something we can approach but never fully occupy, but also -- and I think this becomes clearer as the book progresses -- a recognition that the idealized objective standpoint must be complemented by a subjective standpoint, in a way that accepts an irreconcilable tension between them.
This is where Nagel's ideas come back into alignment with your own, on the poverty of the mechanistic view. The role of subjectivity in science is sometimes thrown about in unsatisfactory ways, as when the observer is said to be inseparable from the observed (I'm thinking of Neils Bohr), or in even less satisfactory ways, as when experiential reports are accepted as valid data (I'm thinking of Mark Solms and Richard O. Prum).
What strikes me as more interesting is the problems that space and time now present for physics. Our intuitive understanding of relativity and quantum mechanics is made difficult -- perhaps even impossible -- by their disruptive implications for our constructs of space and time. There seems to be a noumenal reality where "everything is everywhere all at once," as Whitehead presciently put it back in 1926. What's interesting is the extent to which we have discovered this reality, and can actually work with it mathematically, even though we can make no sense of it conceptually.
"Kant's reasons seem to have to do with the limits imposed on us by certain mental structures required to make sense of the appearances: structures such as space, time, and I guess causality, beyond which (as you've very effectively illustrated) our thoughts simply cannot go."
Yes, that's right. And causality too, though that's not an a priori form but one of the 12 categories of understanding. (Don't ask me what the difference is. I suspect the forms are somehow more fundamental, but I could be wrong.)
I'll keep going with Nagel for sure. I'm especially curious to see what he says about the meaning of life.
"What's interesting is the extent to which we have discovered this reality, and can actually work with it mathematically, even though we can make no sense of it conceptually."
This is one of my questions about where science is going, and I wonder what it means when its theories make no sense conceptually. It seems less clear that science is really about discovering "things in themselves" than about the math. Since I couldn't possibly understand the math so I have to rely on what experts say it means, and I assume the math reveals something that can't be put into a convenient metaphorical description for the general public. But when the concepts get this crazy, I start wondering how the math is supposed to describe reality when the reality it describes is utterly nonsensical. It makes me wonder if anyone is concerned about what counts as making sense, what a theory is supposed to account for.
I guess I don't like the nonsensical or incomprehensible. Mystery is okay, but not absurdities. But I'm just a curmudgeon who thinks theories are supposed to make sense and the fact that they're incomprehensible should mean something got screwed up along the way, time to go back to the drawing board. (To give you some idea of what a big stick in the mud I am, I nearly walked out of a math class on imaginary numbers.)
"Conceptually" might be the the wrong word. I meant that the reality uncovered through our math has begun to defy our intuitions. Possibly this has something to do with imaginary numbers (I once wrote an Idle Speculation about that). The square root of a negative number is inconceivable, in the same way that being outside space or time is inconceivable. And yet if you look into modern physics, you find things that appear to be outside space and time as we understand it -- things that aren't anywhere in particular, that do not exist at any particular time, that confound and frustrate our intuitions of the way the universe and its contents are supposed to behave.
It's so bad that for a long time, physicists took refuge in a "shut up and calculate" mode. The impressive thing is that the calculations worked. We appeared to be dealing with a reality that hung together in some important way, but of which we could form no intuitive conception. Calling the math "nonsensical" isn't really fair. What it says may seem nonsensical, but what it does is deeply persuasive.
To me this sounds a lot like some sort of window on a noumenal world. The question then is what we mean when we call it "inaccessible." Does being able to manage it using extremely abstruse and indirect methods count as "access," even though we are doomed to draw a blank on the phenomenology?
"Calling the math "nonsensical" isn't really fair. What it says may seem nonsensical, but what it does is deeply persuasive."
I didn't mean to call the math nonsensical. I assume that's what must make sense, at least for those doing it (I'm in no position to evaluate that). It's the descriptions that come after that I was talking about. (Although imaginary numbers? I dunno...)
"Does being able to manage it using extremely abstruse and indirect methods count as "access," even though we are doomed to draw a blank on the phenomenology?"
Not if we're talking about Kantian noumena. Math can't access noumena. Math is too human. This is where I have to disagree with Nagel's characterization of his own position. He says he wants to preserve Kantian noumena while saying we can know some of it via primary qualities—but I think that means we're not talking about Kantian noumena anymore. That's precisely where things get confused, and I'm assuming it's why people think they're Kantian when they're not. I think Nagel could have said that Kant took the concept of noumena too far, and that would have been better.
But leaving Kant aside, I think using indirect methods is fine for understanding what I think of as objective or scientific reality. I would point out that math is not outside of us, though.
Personally, I would prefer: "Sorry, can't explain it, but the math makes sense" to wild attempts to describe what the math is doing in phenomenological terms.
No discussion of imaginary numbers and reality would be complete without mentioning some recent results in quantum research. For most of mathematical history, they were regarded as a fictional convenience, which could be worked around if necessary -- even in the famous Schrodinger equation. But in 2021 some researchers determined that in certain quantum situations, they cannot be worked around:
“They are not a mere mathematical artifact,” says study co-author Scandolo. “Complex numbers really do exist and have operational meaning.”
Was going over the thread and noticed that the notion of "imaginary" numbers popped up. In addition to their apparent necessity in quantum mechanics, they're necessary to preserve a fundamental theorem of algebra: that all polynomials have at least one root. That is, all polynomials have some value of 'x' that allows them to evaluate to zero.
Obviously, a polynomial like x^2-4=0 has roots at x=+2 and x=-2, but what about one like x^2+4=0? What possible value of 'x' can be squared to give us the -4 we need to make the thing equal zero? All squares are positive.
Enter the complex numbers. If x=2i, then x-squared is -4.
If you're interested in more, here is a blog post I wrote that gets into the details:
How is it that multiplying to negative numbers gives us a positive number? Multiplying two positive numbers certainly doesn't give us a negative number.
The sad thing is that they were ever called "imaginary".
We've discussed some of this in the past, and I think you know I'm a hard-core realist while also accepting Kant's basic premise about noumena and phenomena. I think the *reason* our minds are conditioned on time and space is because our brains evolved in a reality in which those are fundamental aspects. (Although I consider time to be axiomatic and fundamental, I'm open to notions about emergent space, but space is still fundamental to our evolutionary context.)
As an aside, Kant died 101 years before Einstein's 1905 paper unifying spacetime. And despite that unification, I think they remain distinct for a number of technical reasons I won't get into.
I thought Jim Owens hit the nail on the head with the word "asymptotic" with regard to what we can know about reality. Scientific discoveries are always contingent on future discoveries, and scientific theories are rarely, if ever, *proven* (indeed, a foundation of science is that theories must be *disprovable* -- falsifiable). Another to put it is that science converges on reality, but never fully gets there.
I like to think of our perception of reality as a "wireframe" model. It's missing a lot, but our perceptions are not necessarily *wrong* so much as crude and fuzzy. I think our success in navigating reality speaks to the, um, reality of reality. Scientific experiments return consistent repeatable results, which is more evidence that reality is real.
Some specific responses that popped up while reading your post:
>> "I would rather solve the problem by denying that Kantian things in themselves are really what we mean when we talk about reality."
Okay, that's fine, but it *is* what I mean when I speak of reality. And I think of reality as axiomatic. There isn't really an argument that demonstrates it conclusively. At some point one must *decide* to deny solipsism and accept the axiom that reality is real. And, as Mike said, it's the simplest conclusion. Every alternative theory I've heard is seems torturously complex, and I give them a hard pass.
>> "But Kantian humility means believing science cannot grasp reality as it is in itself—at all."
Which just means most scientists, whatever they claim, aren't really Kantian. Hell, most scientists aren't philosophers much at all (which is theirs and science's loss).
As I think you know, I quite agree about the mechanistic view of the world being a problem. One thing that surprises me a little about the faith in science solving all mysteries is that we already know that doesn't appear to be possible. Heisenberg (uncertainty), Godel (incompleteness), Cantor (uncountable infinity), and Turing (the halting problem) have demonstrated this conclusively long ago.
Even the reality we reach for in the abstract we cannot fully ever grasp.
And I agree that, by objectivity, we generally mean an attempt to overcome our biases. "Objective" data is (hopefully) information that comes from instruments, tests, or experiments with repeatable results. The notion of actually subtracting ourselves from the world was moribund long ago. There remains a belief in quantum physics (not one I share) that consciousness is crucial to the actualization of reality.
Lastly, I've very much liked what I've read of Nagel. I know some take issue with it (which puzzles me), but I thought his famous paper, "What is it like to be a bat?" is a cornerstone of the theory of consciousness.
[Man, Substack leave a lot to be desired when it comes to commenting. Tiny edit window and apparently no ability to use HTML. Phooey on that! Stoneage!]
"And I think of reality as axiomatic. There isn't really an argument that demonstrates it conclusively. At some point one must *decide* to deny solipsism and accept the axiom that reality is real."
Denying Kantian 'things in themselves' (remember, unknowable) wouldn't necessarily amount to solipsism, the belief that only "my" mind can be said to exist. I can't think of any philosopher who is a proponent of solipsism. Descartes came close, then quickly backed out. You can be a scientific instrumentalist or an idealist and believe that in order for a theory to qualify as a scientific it must be falsifiable and should be consistently testable with repeatable results. Idealism doesn't deny physical objects when we're talking about them in the colloquial or common sensical way, but instead denies the theoretical interpretation of the physical as something fundamentally distinct from mind altogether. It doesn't entail the destruction of objectivity, it just situates that objectivity within reach of all minds and no mind in particular. I would argue idealism is more parsimonious since it eliminates the problem of how the abstract physical world of things in themselves causes phenomena, which in the Kantian view is unsolvable in principle.
Now there might be some reason why we need to believe in Kantian things in themselves, but so far I'm not aware of it.
When you say "science converges on reality, but never fully gets there", it makes me think your views align more with Nagel than Kant. If you find yourself wondering what book to read next, I think you'd like The View from Nowhere, especially since you like his essay.
"There remains a belief in quantum physics (not one I share) that consciousness is crucial to the actualization of reality."
The whole quantum physics consciousness thing is so bizarre to me I can't even begin to weigh in on that. I wonder if they think of consciousness in the "what it's like to be a bat" way when they say it's crucial to the actualization of reality?
Substack does feel a bit stone age, doesn't it? I have mixed feelings about that. On the one hand, formatting limitations save time and keep things simple. On the other hand, once you get used to all the cool formatting options on Wordpress and it's hard to let go of those things. I get irritated that I can't do justified text or move images to the left or right when I'm drafting a post on Substack. I suspect if I did the formatting elsewhere and used the "Poetry block" button I could just drop it in and keep my formatting, but that just sucks. Oh, I noticed on WP they started allowing you to drop in videos in the little comments reply boxes rather than going back to your own dashboard comments section. Not sure if I said that right. Anyway, WP is sort of fun to tinker with when it comes to formatting. I like the "before and after" thing they added for photos. But yeah, a bit of a time waster too.
>> "Denying Kantian 'things in themselves' (remember, unknowable) wouldn't necessarily amount to solipsism,..."
I agree. I see denying solipsism as the first step towards realism. As you go on to say, there are many points of view one can take from that point.
>> "Idealism [...] denies the theoretical interpretation of the physical as something fundamentally distinct from mind altogether."
Which is exactly my problem with it. Although, for me, it depends on the exact form of idealism. I agree with Kant's general proposition, that all we can know is phenomena, and I certainly agree that our minds are part of the physical world and not literally distinct (although the notion of transcendental souls intrigues me). I firmly believe that phenomena arise from noumena and are, to a degree, accurate, albeit dim, perceptions of noumena. Through a glass darkly, perhaps, but not in any way illusions.
What I disagree with are forms of idealism that put mind *above* physical reality. For me, the flow is strictly one way, from noumena to phenomena.
>> "I would argue idealism is more parsimonious since it eliminates the problem of how the abstract physical world of things in themselves causes phenomena, ..."
That reminds me a bit of the claim that the Many World Interpretation of quantum mechanics is more parsimonious because it eliminates the vexing problem of wavefunction collapse. True as far as it goes, but for me not so much in the bigger picture. The MWI ends up having a lot of baggage that makes it anything but parsimonious.
I think, too, that many forms of idealism also turn out to come with baggage that complicates things. For one, as you say, what is the source of phenomena? Given their universality and repeatability, how can we deny that they arise from something valid? The fact that science and technology work to me is a strong argument in favor of noumena. Any denial must explain that consistency, predictability, and universality.
>> "Now there might be some reason why we need to believe in Kantian things in themselves, but so far I'm not aware of it."
If not noumena, then what? From where do phenomena arise?
I'm struck by how one of our first experiences as infants is the discovery that the physical world is persistent. If we put an object someplace, it remains there even if out of sight, even if we forget about it only to discover it much later.
And I'm struck by how well our understanding of the material world allows us to manipulate it and predict its behavior. Science, at root, is nothing more than the codification of the persistent patterns we discover. No doubt I'm more in Nagel's camp on this. I suspect most with a scientific bent are. For all that he contributed, I don't think Kant was infallible. To me, he works "under the microscope" but seems to fail in the larger picture. For instance, the Categorical Imperative works pretty well in specific isolated cases but seems intractable when applied to the real world. Likewise, his noumena/phenomena division works great in the abstract but seems to ignore the converging of the consensus of science.
>> "The whole quantum physics consciousness thing is so bizarre to me I can't even begin to weigh in on that."
Indeed, and while I do suspect quantum behavior may turn out to be important for consciousness, that wasn't what I was referring to. Quantum mechanics presents a "fuzzy" reality that only crystalizes when we observe/measure/view it. This fuzziness seems real, not a product of our technological limitations. That crystallization is called the "collapse" (or "reduction") of the wavefunction, and it's one of the biggest mysteries in quantum mechanics (it's called "the measurement problem").
Something that was debated was whether human consciousness was a necessary part of this. It is, in fact, a kind of idealism -- consciousness being required for reality to take shape. It's generally understood now that collapse/reduction occurs when a quantum system interacts with *any* classical system, and consciousness is not required. (That said, some still think it is.)
An interesting question then concerns the state of the universe in the 13.8 billion years before our consciousnesses evolved. Some attribute it all to the Mind of God.
Hope it doesn't seem like I'm getting into petty quibbling, but I think there's a big conceptual difference between saying "noumena = unknowable" vs. "noumena = dimly perceived or indirectly known". Kant would never say we can have "perceptions of noumena", not even dim ones. But this is confusing for those trying to understand what Kant means, because he's not consistent. Sometimes noumena seems to be equivalent to the indirectly known objects of science, other times noumena seems to be a further removed reality about which nothing whatsoever can be said.
Here's my interpretation of Kant:
If we take into account the problems Kant was trying to solve—saving causality from Hume and matter from Berkeley—I think his version of noumena must be taken to be a realm entirely outside the bounds of scientific investigation.
1. Science understands space and time as features of the world itself. But Kant says space and time are not features of the world itself, but instead necessary features of our minds—if we don't interpret him this way, then we're back to Berkeley's criticism of matter (as extension in space).
2. Science takes it for granted that the physical world in itself causes our perceptions or representations. Kant says causality can only apply to our representations, not to the world as it is in itself. This was an answer to Hume, who pointed out that causality does not inhere in the world itself—there is no necessary connection between events. All we can say is one event consistently followed another in the past. (We don't know if the sun will rise tomorrow).
3. Science understands itself as making progress towards indirect knowledge of physical reality. Given the above interpretation of Kant, it doesn't make sense to say science has indirect knowledge of reality. That would be applying causality outside the bounds of our representations.
Why does nearly everyone, including Chalmers, seem to think Kant's views are compatible with our scientific endeavor? The problem is that Kant contradicted himself on many occasions, and not just regarding this. (The spine of copy of the Critique of Pure Reason is split in several places and taped back together from all the times I've thrown it across the room in frustration.) He really wanted clear the way for a scientific view of reality by addressing the skepticisms regarding causality and matter, but I think his answers undermined the goal he set out to achieve.
"if not noumena, then what? From where do phenomena arise?"
They arise from a concept of "things in themselves" which is not Kantian and doesn't require that we think of objectivity in the most extreme sense. Things in themselves doesn't need to be completely on the other side of all possible experience. When we say a scientific theory is successful, it's because it works—it provides the technological goodies, it fulfills certain requirements of scientific theories like consistency and predictability, falsifiability, simplicity and certain aesthetic qualities like elegance.
"I'm struck by how one of our first experiences as infants is the discovery that the physical world is persistent. If we put an object someplace, it remains there even if out of sight, even if we forget about it only to discover it much later."
From a Kantian view, all of this is phenomena. The persistent object is not a thing in itself.
I hope this Kantian noumena stuff is starting to seem extreme? You see, this is exactly what I mean when I say the concept of objectivity is already within our experience. It's what you're talking about here. The physical world is persistent, and that is experienced.
"Categorical Imperative works pretty well in specific isolated cases but seems intractable when applied to the real world."
Totally. Kantian ethics was got me really interested in philosophy. I was intrigued by how a system that seemed logically unassailable could be such an intuitive failure.
"Something that was debated was whether human consciousness was a necessary part of this. It is, in fact, a kind of idealism -- consciousness being required for reality to take shape. It's generally understood now that collapse/reduction occurs when a quantum system interacts with *any* classical system, and consciousness is not required. (That said, some still think it is.)"
Is it consciousness—phenomenal experience—that's really being evaluated in these theories? I've been wondering about this. It seems like they're just talking about a specific theoretical viewpoint, but it's not clear to me what they're talking about when they say 'consciousness'. I guess what I'm asking is, could there be an equivocation going on here?
>> "Kant would never say we can have 'perceptions of noumena', not even dim ones."
Right. What I mean by "dimly" is something akin to how we "see" the wind by seeing its effect on things. Our phenomena are the direct result of noumena, and I think we can infer things about them from the phenomena they cause. No noumena, no phenomena.
If we place noumena entirely outside the bounds of scientific investigation, then I wouldn't grant them any reality at all. What's presented then seems a weird dualism. So, if I'm to take Kant seriously, I have to go with the (to me sensible) "indirectly known objects" interpretation.
Science would generally consider Hume's denial of causality incorrect. The speed of light, the ultimate speed limit, is more properly called the speed of causality. For instance, the notion that we don't know for sure the Sun will rise tomorrow is silly in light of our understanding of the Solar System. For the Sun to *fail* to rise would require a seriously catastrophic event. That the Sun rises is no longer a matter of "well, it always did in the past." We have a physical basis for it now.
>> "The problem is that Kant contradicted himself on many occasions, and not just regarding this."
Yes, and I think it's a mistake to attribute perfection to the analysis of many early philosophers. There seems, at least sometimes, a reverence for them that assumes contradictions or things that aren't clear are due to our inability to understand what these paragons of philosophical excellence said. But they were human, and many of them predate scientific understanding, and I think should be taken with a shaker of salt.
>> "I hope this Kantian noumena stuff is starting to seem extreme?"
Absolutely! It always did. Transcendental Idealism, to me, is nothing more than the (now trivial) observation that all we can ever know is what we obtain from phenomena (and perhaps some a priori abstractions that don't require phenomena -- math, mostly).
>> "I was intrigued by how a system that seemed logically unassailable could be such an intuitive failure."
I kind of came at it bassackwards. My first perception of the CI was negative, but it was through thinking about it that I realized it's a pretty good ethical razor for specific acts.
>> "Is it consciousness—phenomenal experience—that's really being evaluated in these theories?"
I don't think it's something that was ever very well thought out. The notion dates back to the early 20th century, and I think they took consciousness as kind of given. It was an attempt to explain the great mystery of wavefunction collapse. The mystery remains, but few, I think, believe that consciousness is a required element.
"Conceptually" might be the the wrong word. I meant that the reality uncovered through our math has begun to defy our intuitions. Possibly this has something to do with imaginary numbers (I once wrote an Idle Speculation about that). The square root of a negative number is inconceivable, in the same way that being outside space or time is inconceivable. And yet if you look into modern physics, you find things that appear to be outside space and time as we understand it -- things that aren't anywhere in particular, that do not exist at any particular time, that confound and frustrate our intuitions of the way the universe and its contents are supposed to behave.
It's so bad that for a long time, physicists took refuge in a "shut up and calculate" mode. The impressive thing is that the calculations worked. We appeared to be dealing with a reality that hung together in some important way, but of which we could form no intuitive conception. Calling the math "nonsensical" isn't really fair. What it says may seem nonsensical, but what it does is deeply persuasive.
To me this sounds a lot like some sort of window on a noumenal world. The question then is what we mean when we call it "inaccessible." Does being able to manage it using extremely abstruse and indirect methods count as "access," even though we are doomed to draw a blank on the phenomenology?
It looks like the right place to me, but maybe not where you meant it to go? Anyway, no worries, and I'm sorry Substack is such a pain. I think it's even more difficult coming from Wordpress. I get annoyed by the lack of formatting features that we're used to at WP.
I tried to comment without being signed in, thinking that a sign-in would be offered as part of the attempt. This theory was half-right. Substack seemed to offer a sign-in, but after I identified myself, it still didn't post the comment. It just kept asking me to sign in again, with the same dialog box. Eventually I twigged that I had to go and sign into Substack elsewhere before I could comment. Yelling "Just post the comment, you stupid f*&%ing thing!" didn't seem to be helping.
That's weird. I never have to sign in. Maybe that's because I never sign out? Well I'm sorry Substack is so annoying. I've noticed weird little glitches with it on other things. Funny that yelling didn't help. That usually does the trick for me!
Is there a reality independent of mind? We can only know anything with our minds. Then it is truly baffling to say we can know mind-independent reality.
I believe this puzzle can be solved only by enquiring into the nature of knowledge itself. <a href="http://shajanmathew.com/2023/11/01/3-what-is-knowledge/">What does it mean to ‘know’ something?</a> Such an enquiry will eventually lead us to conclude fundamental reality is neither material nor mental. It can only be described as unknowable 'nature-in-itself’.
I looked at the Nagel book at Amazon, and it's $31.49 for the Kindle version (more for paperback and almost $75 for hardcover). So, I don't think I'll get it anytime soon. I did buy /Mind, Language And Society/, by John Searle, and so far am really enjoying it (just read the first section so far). It's in large part his defense of external realism and a critique of idealism.
I cracked up when I read this bit:
"Famous examples [of what he views as philosophically weak arguments] are David Hume’s refutation of the idea that causation is a real relation between events in the world, Bishop George Berkeley’s refutation of the view that a material world exists independently of our perceptions of it, and the rejection by Descartes, as well as many other philosophers, of the view that we can have direct perceptual knowledge of the world."
It's funny that the book is still so expensive. There was a receipt in my husband's copy, which he bought in the 90s, and I was surprised that he paid 20 bucks for it that long ago (and then clearly didn't read it).
Here's a short paper by Searle, in case anyone's interested:
I haven't gotten to a part where he specifically argues against Hume, but in the chapter "Skepticism, Knowledge, and Reality" he says that most Idealist arguments depend on illusion or science (the latter being most common these days).
Illusion arguments boil down the impossibility of distinguishing what he calls the veridical case versus "illusions, hallucinations, delusions and so on." He goes on to say, "The simplest version that I know of is to be found in Hume. He thought that naive perceptual realism was so easily refutable that he dismissed it in a few sentences." One example is, that if you cross your eyes, you see double, but this doesn't mean the *world* doubled. Since we can't trust these perceptions to be veridical, or distinguish them from false perceptions, we can't trust our perceptions. He argues:
"But why should a single experience be all I have to go on? [...] Any single experience only makes the kind of sense to me that it does because it is part of a network of other experiences, and it goes on against a Background of taken-for-granted capacities I have for coping with the world. If that is right, then the single experience, considered in isolation by itself, is not sufficient to make the distinction between veridical perception and hallucination."
Which is very similar to what I've argued about external realism. Individual cases cannot be the basis for our analysis of how reality works. Our understanding of reality is a consensus that is convergent (and contingent). Our ability to manipulate and predict physical behavior, as well as its consistency and universality, strongly support external realism.
The science argument against realism is essentially what Kant said about transcendental idealism -- all we can know are phenomena through the mechanism of our senses, and we can know *nothing* about noumena. But that we can give an accurate and testable account of *how* those senses produce phenomena argues to the reality of noumena and does tell us *something* about them. (As I've said before, I think we get a "wireframe" view of reality that misses much but is not entirely inaccurate. That we can successfully navigate a persistent reality says something about that reality.)
From a modern physics perspective, Hume's rejection of causality is especially weak. In the three centuries since Hume, we have developed a very good understanding of it, including things like light cones which limit what can cause something (it must be in the past light cone), as well as an understanding of particle physics -- causality at its most fundamental level.
I liked the paper you linked to. It's a pretty good answer the question of epiphenomenalism. As I think you know, I have spiritual suspicions, but those are on the faith and belief side. On the physical side, I quite agree with Searle about consciousness. It's an emergent property of the brain, but not distinct from it.
Oh, I forgot to say, you should check and see if it's available at your library. If not, you could request it. He's a pretty dang famous philosopher, so I would think they'd honor that request.
To me objectivity is the simplest reliable consensus model. "Simplest" is important here because I think it leaves no reason for us to entertain unknowable "things in themselves". There may be unknowable aspects of things, but if so, there's no reason to suppose any guesses we make about them will be accurate. So saying they *might* exist seems to do no work.
The whole notion of unknowable reality feels like a device to preserve cherished notions, to continue holding that they're true despite the lack of evidence. And it seems like this goes all the way back to Kant. I found these points in the SEP entry on Kant pretty interesting.
"The problem is that to some it seemed unclear whether progress would in fact ensue if reason enjoyed full sovereignty over traditional authorities; or whether unaided reasoning would instead lead straight to materialism, fatalism, atheism, skepticism (Bxxxiv), or even libertinism and authoritarianism (8:146). "
"Yet the original inspiration for the Enlightenment was the new physics, which was mechanistic. If nature is entirely governed by mechanistic, causal laws, then it may seem that there is no room for freedom, a soul, or anything but matter in motion. This threatened the traditional view that morality requires freedom. We must be free in order to choose what is right over what is wrong, because otherwise we cannot be held responsible. It also threatened the traditional religious belief in a soul that can survive death or be resurrected in an afterlife. So modern science, the pride of the Enlightenment, the source of its optimism about the powers of human reason, threatened to undermine traditional moral and religious beliefs that free rational thought was expected to support. This was the main intellectual crisis of the Enlightenment.
The Critique of Pure Reason is Kant’s response to this crisis."
https://plato.stanford.edu/entries/kant/#CriEnl
Personally, I think Kant's mistake, and the mistake many philosophers make, is in trying to find a way to preserve the original naive versions of these concepts, rather than facing the music and scrutinizing them. Of course that's coming from a philistine who thinks the mechanistic stance is the way to go. Granted, sometimes a purely mechanistic explanation isn't available in science, but history seems to indicate we'll get one if we just be patient. It isn't always a comforting view. Although if we understand the mechanics of reality sufficiently, we can hope to make our own comfort.
But always interested in any arguments showing these views may be wrong.
Thanks for those SEP extracts. Freedom is something I didn't have the space to get into, but I think that's an area where the difference between the modern view and the ancient one comes into even sharper focus. Nagel has a section on freedom and autonomy as well which I just started reading last night, and it reminds me of just how much the idea of freedom has changed and has become such an intractable battle between the the subjective sense that we have free choice and responsibility as opposed to the objective sense that we don't. The problem all but disappears with ancient virtue ethics, though. Freedom wasn't about the ability to make choices. Who cares about being able to choose if you don't know what the best choice is? For them, freedom is knowledge. Their ethics might be called vague and somewhat lawless (which Kant would not have liked), but I think that view makes more sense than anything.
You could say Kant really drew a line in the sand between religion and reason. I want to say it's in the antinomies where he argues that you can't know whether the soul or God or freedom exist or don't exist. These are matters of faith, not reason. He imagined he was saving both, but I don't think he did anything for religious belief. His ethical system was a noble attempt to save autonomy, but I can't think of anyone who buys into the categorical imperative (because Nazis).
The problem with science right now, in my opinion, is that it's not clear the mechanistic framework can in principle explain what needs to be explained. I was watching a debate on the afterlife in which Sean Carroll (I think that's who it was) argued in the same way, that the answers are coming. But you can always say the answers are in the future. These questions have been around for centuries and I don't see even the beginnings of an answer, which makes me think it doesn't seem likely a mechanistic understanding can accommodate the fullest reality. Don't get me wrong, I don't want naive concepts either, and I'm certainly not committed to certain religious beliefs like the immortality of the soul and the like, but I don't think saying subjective experience is not illusory is naive. That said, I'd be perfectly happy with science doing what science does so long as certain prominent figures stop claiming science has everything in place to figure these things out (cough, cough...Sean Carroll...cough) someday.
I meant to say that since you seem to be very much in the know when it comes to what counts as scientific these days, it's nice to hear the "simplest consensus model", or at least some form of consensus, is not something that's seen as an affront to what science is trying to do. I really wasn't sure how views about consensus-as-objectivity would go over, as that's how I see it too. (I remember a physics professor throwing a hissy fit when we were discussing instrumentalism.)
Also—totally irrelevant—I saw that the Nagel book is ranked #22 on Amazon for "German Language Instruction", which reminded me of our conversation about that and made me laugh.
https://www.amazon.com/View-Nowhere-Thomas-Nagel/dp/0195056442
I hadn't heard that about ancient attitudes toward free will. Interesting. And it's closer to my own compatibilist conception of having the capacity for forethought. A lot of the contemporary debate seems tangled up with theology and the idea of a judgment day. Some ancient societies seemed concerned about that (some periods in Egypt for instance), but not all. But it also gets to something I'm increasingly on the watch for: projecting our own contemporary issues onto what people wrote millenia ago. It seems like getting into the details often makes that dicey.
My attitude toward moral theories is that none of them should be adopted dogmatically, none of them are "true" in that sense, but many of them have pragmatic use. So for many potential situations, the categorical imperative, basically can we be consistent about it, can be useful, just not in any absolute sense where we have to tell the truth to the Gestapo about the refugees we're hiding.
Carroll was in a debate about the afterlife? I would imagine he repeated one of his favorite points, that we have a complete understanding of everyday physics, which doesn't leave much room for any non-physical stuff. I think he's right, although people tend to overinterpret that, that because we have that understanding, we also understand all the mechanisms built on top of it, which we definitely don't. My only unease with his usual presentation is it seems to rule out unknown unknowns, which I think we always have to admit are a thing.
It's often not clear how to explain things mechanistically. Quantum mechanics remains the one people think defies the mechanistic philosophy, although there are interpretations that preserve it. But another big one people talk about, consciousness, I think gets dissolved once we accept that our inner sense is just as fallible as the outer ones. It doesn't mean consciousness doesn't exist, but it does mean it isn't what we tend to intuitively assume it is.
Instrumentalism isn't popular among scientists. It's hard to be motivated to do the often difficult (sometimes dangerous) data gathering if you don't see yourself as in pursuit of truth. Although there are more instrumentalist scientists than is often assumed, but typically among theorists than experimentalists. Myself, I remain in the structural realist column, although a lot depends on what we mean by "real". In the end, "real" seems like the model we expect all the other "real" models to reconcile with.
Amazon is funny. I wonder why they struggle so much with categorizing philosophy. Is it that hard a category to understand? But I guess Politics and Social Sciences is better than the Spirituality section my local B&N puts them in (at least the time I went there, which is several years ago at this point).
I tend to take Aristotle as the key figure when I talk about ancient morality, but of course there are differences amongst them. I think comparing him to Kant reveals the split between ancient and modern ethics most clearly. For the ancients, morality wasn't about free will. It's not clear whether this was even a problem (in our sense) in Homer. Nature was simply taken as given—clearly there are things you can't change and things that make you who you are, for better or worse. What matters most for Aristotle is happiness, which he takes to be the highest good for us. Kant, on the other hand, is explicit in saying we should not take happiness into consideration. One of the most interesting things about Aristotle's view is that virtue, or excellence of character, comes about by habit. You are what you habitually do. There are certain things you can't help about who you are, but this doesn't mean you can't live whatever the good life means for you. Each of us has to strive to find what moderation means for us. For instance, if I start eating like an Olympic athlete, that won't be good for me because I don't burn that many calories (seeing as I tend to prefer sitting on my lazy butt in front of the computer as I am now). The good life isn't about the freedom to choose or escaping nature. It's about knowing what to do within the confines of nature, especially one's own. Whatever your background or limitations, you can and should strive to be the sort of person who knows how to assess various situations appropriately for you. Which means—contrary to Kant—there can't be rules of conduct:
"But this must be agreed upon beforehand, that the whole account of matters of conduct must be given in outline and not precisely, as we said at the very beginning that the accounts we demand must be in accordance with the subject-matter; matters concerned with conduct and questions of what is good for us have no fixity, any more than matters of health. The general account being of this nature, the account of particular cases is yet more lacking in exactness; for they do not fall under any art or precept but the agents themselves must in each case consider what is appropriate to the occasion, as happens also in the art of medicine or of navigation."
https://classics.mit.edu/Aristotle/nicomachaen.2.ii.html
I imagine many people today actually believe what Aristotle says about morality without knowing a thing about him. His views seem fairly sophisticated in many ways. Even the concept that you are what you do, I imagine that advice is all over the place in our self-help books (I don't read self-help books, but I get a sense of what they're like from the subtitles on their covers.)
Here's part of the Sean Carroll debate. I can't find the whole thing:
https://www.youtube.com/watch?v=-gJfxO7Ik2A
I think for me at least it's less about what Carroll says and more about his smug, know it all demeanor. But I'm not too keen on what he says either.
"Quantum mechanics remains the one people think defies the mechanistic philosophy, although there are interpretations that preserve it."
I forget how Chalmers puts it, but I liked what he said about those who try to tie consciousness to quantum mechanics. He boils down their arguments to something like, consciousness is weird, QM is weird, so they must be connected.
"once we accept that our inner sense is just as fallible as the outer ones" It sounds like you're a hardcore skeptic, then!
Yeah, I can understand why those who do the grueling lab work that makes up a great deal of science might not like to be told they're not discovering the nature of reality. It makes sense that the more theoretical and philosophical scientists would be more amenable to instrumentalism.
Amazon, I think, is just a total mess. Actually, I think it's becoming harder and harder to search the internet for things. It seems like a bunch of irrelevant junk is the first stuff to pop up. The B&N thing is so funny and sad at the same time. I've seen that weird categorization in other bookstores as well, back when there were bookstores. Americans know so little about philosophy that they think it makes sense to put philosophy in the "metaphysical" (woo woo crystals) section.
The impression I get of Aristotle is he didn’t have the hangups later writers did due to centuries of monotheism. His approach definitely seemed like a sort of self help, rather than trying to establish some abstract notions of “right” and “wrong”. I wonder what he would have thought of the modern moral realist vs antirealist debates.
Thanks for the debate link. Looks like it was a while ago, closer to the New Atheism period. I think Carroll’s presentation has softened somewhat over the years, probably due to age more than anything. Not that non-physicalists are any happier with him.
On quantum mechanics and consciousness, yeah. On the one hand, it’s easy to see why people go there. I think it crosses the mind of anyone learning about the measurement problem for the first time. And scientists themselves toyed with the idea in the early decades of quantum theory. But it’s the allure of the unknowable reality and what can be tucked away in it that I think makes at least some people passionate about it.
On consciousness, I am a skeptic, but only toward a theory of consciousness as something fundamental, unanalyzable, and inaccessible to third party observation. I do think consciousness is extremely *difficult* to analyze and observe objectively. A nuanced distinction, but one that means the difference between an impossible problem and an array of scientifically tractable ones.
I’ve never found Amazon particularly easy to peruse, although I can usually find things if I already know what I’m looking for. But yeah, there’s a growing sentiment that Google searches are getting worse. I remember search engines before Google, which were pretty useless because they sold the highest results. Google at least labels their sold spots, but I feel like I need to scroll past that junk to get to the real stuff. But I wonder if Google has started slipping in the endless arms race between them and the SEO optimizers.
Yeah, I've been bugged by Google Search for a few years now. Obviously, I'm not alone in that. Besides all the SEO stuff, I've wondered if the interweb has just gotten too big and too polluted with noise for effective searching. Searches for answers turn up more people guessing than knowing. Tragedy of the Commons!
Nagel is defending realism within the larger purpose of the book. He is trying to establish the possibility, not to say the credibility, of an objective viewpoint for beings whose subjectivity is inescapable. Inevitably, this leads him into Kantian questions about whether knowledge of reality in itself is possible. Here he opts for a weak rather than a strong realism, as you've noted. His position is that while reality is unknowable, it must be true that either our conception has something to do with it, or nothing at all to do with it; and he sees no special reason to assume the latter. On the contrary, it seems more reasonable to him that we should suppose our conception has some relation to reality, even though technically it may be unknowable. It's not an especially defensible position, but as far as he's concerned, neither is its opposite, taken absolutely; and if he has to choose, he would lean towards the more common-sense view.
The whole discussion is to one side of his main thesis. His reasons for contemplating the unknowability of reality are not Kant's, as far as I can tell. You have a much better command of the epistemological tradition than I do, so I'm treading cautiously here, but Kant's reasons seem to have to do with the limits imposed on us by certain mental structures required to make sense of the appearances: structures such as space, time, and I guess causality, beyond which (as you've very effectively illustrated) our thoughts simply cannot go.
Nagels' reasons are different. They have to do with the fact of our subjectivity, which we can never escape to get a truly objective view. It is this, not the limitation on our abstract conceptions, that makes objective knowledge impossible in principle. I think Nagel largely concedes the abstract limitations, but he doesn't accept them as conclusive, in the weakly realist sense I've described. His own puzzle stands largely outside the tradition; or rather, in the less popular part of the tradition where we find Leibniz, the part that grants a genuine place to subjectivity. While defending realism in a sideways fashion against the Kantian tradition, his problem is how to maintain it once we accept the inescapability of the subjective viewpoint. The solution seems to involve both an asymptotic conception of the objective view, as something we can approach but never fully occupy, but also -- and I think this becomes clearer as the book progresses -- a recognition that the idealized objective standpoint must be complemented by a subjective standpoint, in a way that accepts an irreconcilable tension between them.
This is where Nagel's ideas come back into alignment with your own, on the poverty of the mechanistic view. The role of subjectivity in science is sometimes thrown about in unsatisfactory ways, as when the observer is said to be inseparable from the observed (I'm thinking of Neils Bohr), or in even less satisfactory ways, as when experiential reports are accepted as valid data (I'm thinking of Mark Solms and Richard O. Prum).
What strikes me as more interesting is the problems that space and time now present for physics. Our intuitive understanding of relativity and quantum mechanics is made difficult -- perhaps even impossible -- by their disruptive implications for our constructs of space and time. There seems to be a noumenal reality where "everything is everywhere all at once," as Whitehead presciently put it back in 1926. What's interesting is the extent to which we have discovered this reality, and can actually work with it mathematically, even though we can make no sense of it conceptually.
"Kant's reasons seem to have to do with the limits imposed on us by certain mental structures required to make sense of the appearances: structures such as space, time, and I guess causality, beyond which (as you've very effectively illustrated) our thoughts simply cannot go."
Yes, that's right. And causality too, though that's not an a priori form but one of the 12 categories of understanding. (Don't ask me what the difference is. I suspect the forms are somehow more fundamental, but I could be wrong.)
I'll keep going with Nagel for sure. I'm especially curious to see what he says about the meaning of life.
"What's interesting is the extent to which we have discovered this reality, and can actually work with it mathematically, even though we can make no sense of it conceptually."
This is one of my questions about where science is going, and I wonder what it means when its theories make no sense conceptually. It seems less clear that science is really about discovering "things in themselves" than about the math. Since I couldn't possibly understand the math so I have to rely on what experts say it means, and I assume the math reveals something that can't be put into a convenient metaphorical description for the general public. But when the concepts get this crazy, I start wondering how the math is supposed to describe reality when the reality it describes is utterly nonsensical. It makes me wonder if anyone is concerned about what counts as making sense, what a theory is supposed to account for.
I guess I don't like the nonsensical or incomprehensible. Mystery is okay, but not absurdities. But I'm just a curmudgeon who thinks theories are supposed to make sense and the fact that they're incomprehensible should mean something got screwed up along the way, time to go back to the drawing board. (To give you some idea of what a big stick in the mud I am, I nearly walked out of a math class on imaginary numbers.)
"Conceptually" might be the the wrong word. I meant that the reality uncovered through our math has begun to defy our intuitions. Possibly this has something to do with imaginary numbers (I once wrote an Idle Speculation about that). The square root of a negative number is inconceivable, in the same way that being outside space or time is inconceivable. And yet if you look into modern physics, you find things that appear to be outside space and time as we understand it -- things that aren't anywhere in particular, that do not exist at any particular time, that confound and frustrate our intuitions of the way the universe and its contents are supposed to behave.
It's so bad that for a long time, physicists took refuge in a "shut up and calculate" mode. The impressive thing is that the calculations worked. We appeared to be dealing with a reality that hung together in some important way, but of which we could form no intuitive conception. Calling the math "nonsensical" isn't really fair. What it says may seem nonsensical, but what it does is deeply persuasive.
To me this sounds a lot like some sort of window on a noumenal world. The question then is what we mean when we call it "inaccessible." Does being able to manage it using extremely abstruse and indirect methods count as "access," even though we are doomed to draw a blank on the phenomenology?
"Calling the math "nonsensical" isn't really fair. What it says may seem nonsensical, but what it does is deeply persuasive."
I didn't mean to call the math nonsensical. I assume that's what must make sense, at least for those doing it (I'm in no position to evaluate that). It's the descriptions that come after that I was talking about. (Although imaginary numbers? I dunno...)
"Does being able to manage it using extremely abstruse and indirect methods count as "access," even though we are doomed to draw a blank on the phenomenology?"
Not if we're talking about Kantian noumena. Math can't access noumena. Math is too human. This is where I have to disagree with Nagel's characterization of his own position. He says he wants to preserve Kantian noumena while saying we can know some of it via primary qualities—but I think that means we're not talking about Kantian noumena anymore. That's precisely where things get confused, and I'm assuming it's why people think they're Kantian when they're not. I think Nagel could have said that Kant took the concept of noumena too far, and that would have been better.
But leaving Kant aside, I think using indirect methods is fine for understanding what I think of as objective or scientific reality. I would point out that math is not outside of us, though.
Personally, I would prefer: "Sorry, can't explain it, but the math makes sense" to wild attempts to describe what the math is doing in phenomenological terms.
No discussion of imaginary numbers and reality would be complete without mentioning some recent results in quantum research. For most of mathematical history, they were regarded as a fictional convenience, which could be worked around if necessary -- even in the famous Schrodinger equation. But in 2021 some researchers determined that in certain quantum situations, they cannot be worked around:
“They are not a mere mathematical artifact,” says study co-author Scandolo. “Complex numbers really do exist and have operational meaning.”
https://science.ucalgary.ca/news/international-team-including-university-calgary-researcher-proves-imaginary-numbers-have-real
Thanks! I’ll check this out.
Was going over the thread and noticed that the notion of "imaginary" numbers popped up. In addition to their apparent necessity in quantum mechanics, they're necessary to preserve a fundamental theorem of algebra: that all polynomials have at least one root. That is, all polynomials have some value of 'x' that allows them to evaluate to zero.
Obviously, a polynomial like x^2-4=0 has roots at x=+2 and x=-2, but what about one like x^2+4=0? What possible value of 'x' can be squared to give us the -4 we need to make the thing equal zero? All squares are positive.
Enter the complex numbers. If x=2i, then x-squared is -4.
If you're interested in more, here is a blog post I wrote that gets into the details:
https://logosconcarne.com/2020/03/23/imaginary-numbers/
The post immediately after it explores it visually. And this post explores how the complex numbers factor into something as basic as -1*-1=+1:
https://logosconcarne.com/2020/05/07/numbers-gotta-number/
How is it that multiplying to negative numbers gives us a positive number? Multiplying two positive numbers certainly doesn't give us a negative number.
The sad thing is that they were ever called "imaginary".
We've discussed some of this in the past, and I think you know I'm a hard-core realist while also accepting Kant's basic premise about noumena and phenomena. I think the *reason* our minds are conditioned on time and space is because our brains evolved in a reality in which those are fundamental aspects. (Although I consider time to be axiomatic and fundamental, I'm open to notions about emergent space, but space is still fundamental to our evolutionary context.)
As an aside, Kant died 101 years before Einstein's 1905 paper unifying spacetime. And despite that unification, I think they remain distinct for a number of technical reasons I won't get into.
I thought Jim Owens hit the nail on the head with the word "asymptotic" with regard to what we can know about reality. Scientific discoveries are always contingent on future discoveries, and scientific theories are rarely, if ever, *proven* (indeed, a foundation of science is that theories must be *disprovable* -- falsifiable). Another to put it is that science converges on reality, but never fully gets there.
I like to think of our perception of reality as a "wireframe" model. It's missing a lot, but our perceptions are not necessarily *wrong* so much as crude and fuzzy. I think our success in navigating reality speaks to the, um, reality of reality. Scientific experiments return consistent repeatable results, which is more evidence that reality is real.
Some specific responses that popped up while reading your post:
>> "I would rather solve the problem by denying that Kantian things in themselves are really what we mean when we talk about reality."
Okay, that's fine, but it *is* what I mean when I speak of reality. And I think of reality as axiomatic. There isn't really an argument that demonstrates it conclusively. At some point one must *decide* to deny solipsism and accept the axiom that reality is real. And, as Mike said, it's the simplest conclusion. Every alternative theory I've heard is seems torturously complex, and I give them a hard pass.
>> "But Kantian humility means believing science cannot grasp reality as it is in itself—at all."
Which just means most scientists, whatever they claim, aren't really Kantian. Hell, most scientists aren't philosophers much at all (which is theirs and science's loss).
As I think you know, I quite agree about the mechanistic view of the world being a problem. One thing that surprises me a little about the faith in science solving all mysteries is that we already know that doesn't appear to be possible. Heisenberg (uncertainty), Godel (incompleteness), Cantor (uncountable infinity), and Turing (the halting problem) have demonstrated this conclusively long ago.
Even the reality we reach for in the abstract we cannot fully ever grasp.
And I agree that, by objectivity, we generally mean an attempt to overcome our biases. "Objective" data is (hopefully) information that comes from instruments, tests, or experiments with repeatable results. The notion of actually subtracting ourselves from the world was moribund long ago. There remains a belief in quantum physics (not one I share) that consciousness is crucial to the actualization of reality.
Lastly, I've very much liked what I've read of Nagel. I know some take issue with it (which puzzles me), but I thought his famous paper, "What is it like to be a bat?" is a cornerstone of the theory of consciousness.
[Man, Substack leave a lot to be desired when it comes to commenting. Tiny edit window and apparently no ability to use HTML. Phooey on that! Stoneage!]
"And I think of reality as axiomatic. There isn't really an argument that demonstrates it conclusively. At some point one must *decide* to deny solipsism and accept the axiom that reality is real."
Denying Kantian 'things in themselves' (remember, unknowable) wouldn't necessarily amount to solipsism, the belief that only "my" mind can be said to exist. I can't think of any philosopher who is a proponent of solipsism. Descartes came close, then quickly backed out. You can be a scientific instrumentalist or an idealist and believe that in order for a theory to qualify as a scientific it must be falsifiable and should be consistently testable with repeatable results. Idealism doesn't deny physical objects when we're talking about them in the colloquial or common sensical way, but instead denies the theoretical interpretation of the physical as something fundamentally distinct from mind altogether. It doesn't entail the destruction of objectivity, it just situates that objectivity within reach of all minds and no mind in particular. I would argue idealism is more parsimonious since it eliminates the problem of how the abstract physical world of things in themselves causes phenomena, which in the Kantian view is unsolvable in principle.
Now there might be some reason why we need to believe in Kantian things in themselves, but so far I'm not aware of it.
When you say "science converges on reality, but never fully gets there", it makes me think your views align more with Nagel than Kant. If you find yourself wondering what book to read next, I think you'd like The View from Nowhere, especially since you like his essay.
"There remains a belief in quantum physics (not one I share) that consciousness is crucial to the actualization of reality."
The whole quantum physics consciousness thing is so bizarre to me I can't even begin to weigh in on that. I wonder if they think of consciousness in the "what it's like to be a bat" way when they say it's crucial to the actualization of reality?
Substack does feel a bit stone age, doesn't it? I have mixed feelings about that. On the one hand, formatting limitations save time and keep things simple. On the other hand, once you get used to all the cool formatting options on Wordpress and it's hard to let go of those things. I get irritated that I can't do justified text or move images to the left or right when I'm drafting a post on Substack. I suspect if I did the formatting elsewhere and used the "Poetry block" button I could just drop it in and keep my formatting, but that just sucks. Oh, I noticed on WP they started allowing you to drop in videos in the little comments reply boxes rather than going back to your own dashboard comments section. Not sure if I said that right. Anyway, WP is sort of fun to tinker with when it comes to formatting. I like the "before and after" thing they added for photos. But yeah, a bit of a time waster too.
>> "Denying Kantian 'things in themselves' (remember, unknowable) wouldn't necessarily amount to solipsism,..."
I agree. I see denying solipsism as the first step towards realism. As you go on to say, there are many points of view one can take from that point.
>> "Idealism [...] denies the theoretical interpretation of the physical as something fundamentally distinct from mind altogether."
Which is exactly my problem with it. Although, for me, it depends on the exact form of idealism. I agree with Kant's general proposition, that all we can know is phenomena, and I certainly agree that our minds are part of the physical world and not literally distinct (although the notion of transcendental souls intrigues me). I firmly believe that phenomena arise from noumena and are, to a degree, accurate, albeit dim, perceptions of noumena. Through a glass darkly, perhaps, but not in any way illusions.
What I disagree with are forms of idealism that put mind *above* physical reality. For me, the flow is strictly one way, from noumena to phenomena.
>> "I would argue idealism is more parsimonious since it eliminates the problem of how the abstract physical world of things in themselves causes phenomena, ..."
That reminds me a bit of the claim that the Many World Interpretation of quantum mechanics is more parsimonious because it eliminates the vexing problem of wavefunction collapse. True as far as it goes, but for me not so much in the bigger picture. The MWI ends up having a lot of baggage that makes it anything but parsimonious.
I think, too, that many forms of idealism also turn out to come with baggage that complicates things. For one, as you say, what is the source of phenomena? Given their universality and repeatability, how can we deny that they arise from something valid? The fact that science and technology work to me is a strong argument in favor of noumena. Any denial must explain that consistency, predictability, and universality.
>> "Now there might be some reason why we need to believe in Kantian things in themselves, but so far I'm not aware of it."
If not noumena, then what? From where do phenomena arise?
I'm struck by how one of our first experiences as infants is the discovery that the physical world is persistent. If we put an object someplace, it remains there even if out of sight, even if we forget about it only to discover it much later.
And I'm struck by how well our understanding of the material world allows us to manipulate it and predict its behavior. Science, at root, is nothing more than the codification of the persistent patterns we discover. No doubt I'm more in Nagel's camp on this. I suspect most with a scientific bent are. For all that he contributed, I don't think Kant was infallible. To me, he works "under the microscope" but seems to fail in the larger picture. For instance, the Categorical Imperative works pretty well in specific isolated cases but seems intractable when applied to the real world. Likewise, his noumena/phenomena division works great in the abstract but seems to ignore the converging of the consensus of science.
>> "The whole quantum physics consciousness thing is so bizarre to me I can't even begin to weigh in on that."
Indeed, and while I do suspect quantum behavior may turn out to be important for consciousness, that wasn't what I was referring to. Quantum mechanics presents a "fuzzy" reality that only crystalizes when we observe/measure/view it. This fuzziness seems real, not a product of our technological limitations. That crystallization is called the "collapse" (or "reduction") of the wavefunction, and it's one of the biggest mysteries in quantum mechanics (it's called "the measurement problem").
Something that was debated was whether human consciousness was a necessary part of this. It is, in fact, a kind of idealism -- consciousness being required for reality to take shape. It's generally understood now that collapse/reduction occurs when a quantum system interacts with *any* classical system, and consciousness is not required. (That said, some still think it is.)
An interesting question then concerns the state of the universe in the 13.8 billion years before our consciousnesses evolved. Some attribute it all to the Mind of God.
Hope it doesn't seem like I'm getting into petty quibbling, but I think there's a big conceptual difference between saying "noumena = unknowable" vs. "noumena = dimly perceived or indirectly known". Kant would never say we can have "perceptions of noumena", not even dim ones. But this is confusing for those trying to understand what Kant means, because he's not consistent. Sometimes noumena seems to be equivalent to the indirectly known objects of science, other times noumena seems to be a further removed reality about which nothing whatsoever can be said.
Here's my interpretation of Kant:
If we take into account the problems Kant was trying to solve—saving causality from Hume and matter from Berkeley—I think his version of noumena must be taken to be a realm entirely outside the bounds of scientific investigation.
1. Science understands space and time as features of the world itself. But Kant says space and time are not features of the world itself, but instead necessary features of our minds—if we don't interpret him this way, then we're back to Berkeley's criticism of matter (as extension in space).
2. Science takes it for granted that the physical world in itself causes our perceptions or representations. Kant says causality can only apply to our representations, not to the world as it is in itself. This was an answer to Hume, who pointed out that causality does not inhere in the world itself—there is no necessary connection between events. All we can say is one event consistently followed another in the past. (We don't know if the sun will rise tomorrow).
3. Science understands itself as making progress towards indirect knowledge of physical reality. Given the above interpretation of Kant, it doesn't make sense to say science has indirect knowledge of reality. That would be applying causality outside the bounds of our representations.
Why does nearly everyone, including Chalmers, seem to think Kant's views are compatible with our scientific endeavor? The problem is that Kant contradicted himself on many occasions, and not just regarding this. (The spine of copy of the Critique of Pure Reason is split in several places and taped back together from all the times I've thrown it across the room in frustration.) He really wanted clear the way for a scientific view of reality by addressing the skepticisms regarding causality and matter, but I think his answers undermined the goal he set out to achieve.
"if not noumena, then what? From where do phenomena arise?"
They arise from a concept of "things in themselves" which is not Kantian and doesn't require that we think of objectivity in the most extreme sense. Things in themselves doesn't need to be completely on the other side of all possible experience. When we say a scientific theory is successful, it's because it works—it provides the technological goodies, it fulfills certain requirements of scientific theories like consistency and predictability, falsifiability, simplicity and certain aesthetic qualities like elegance.
"I'm struck by how one of our first experiences as infants is the discovery that the physical world is persistent. If we put an object someplace, it remains there even if out of sight, even if we forget about it only to discover it much later."
From a Kantian view, all of this is phenomena. The persistent object is not a thing in itself.
I hope this Kantian noumena stuff is starting to seem extreme? You see, this is exactly what I mean when I say the concept of objectivity is already within our experience. It's what you're talking about here. The physical world is persistent, and that is experienced.
"Categorical Imperative works pretty well in specific isolated cases but seems intractable when applied to the real world."
Totally. Kantian ethics was got me really interested in philosophy. I was intrigued by how a system that seemed logically unassailable could be such an intuitive failure.
"Something that was debated was whether human consciousness was a necessary part of this. It is, in fact, a kind of idealism -- consciousness being required for reality to take shape. It's generally understood now that collapse/reduction occurs when a quantum system interacts with *any* classical system, and consciousness is not required. (That said, some still think it is.)"
Is it consciousness—phenomenal experience—that's really being evaluated in these theories? I've been wondering about this. It seems like they're just talking about a specific theoretical viewpoint, but it's not clear to me what they're talking about when they say 'consciousness'. I guess what I'm asking is, could there be an equivocation going on here?
>> "Kant would never say we can have 'perceptions of noumena', not even dim ones."
Right. What I mean by "dimly" is something akin to how we "see" the wind by seeing its effect on things. Our phenomena are the direct result of noumena, and I think we can infer things about them from the phenomena they cause. No noumena, no phenomena.
If we place noumena entirely outside the bounds of scientific investigation, then I wouldn't grant them any reality at all. What's presented then seems a weird dualism. So, if I'm to take Kant seriously, I have to go with the (to me sensible) "indirectly known objects" interpretation.
Science would generally consider Hume's denial of causality incorrect. The speed of light, the ultimate speed limit, is more properly called the speed of causality. For instance, the notion that we don't know for sure the Sun will rise tomorrow is silly in light of our understanding of the Solar System. For the Sun to *fail* to rise would require a seriously catastrophic event. That the Sun rises is no longer a matter of "well, it always did in the past." We have a physical basis for it now.
>> "The problem is that Kant contradicted himself on many occasions, and not just regarding this."
Yes, and I think it's a mistake to attribute perfection to the analysis of many early philosophers. There seems, at least sometimes, a reverence for them that assumes contradictions or things that aren't clear are due to our inability to understand what these paragons of philosophical excellence said. But they were human, and many of them predate scientific understanding, and I think should be taken with a shaker of salt.
>> "I hope this Kantian noumena stuff is starting to seem extreme?"
Absolutely! It always did. Transcendental Idealism, to me, is nothing more than the (now trivial) observation that all we can ever know is what we obtain from phenomena (and perhaps some a priori abstractions that don't require phenomena -- math, mostly).
>> "I was intrigued by how a system that seemed logically unassailable could be such an intuitive failure."
I kind of came at it bassackwards. My first perception of the CI was negative, but it was through thinking about it that I realized it's a pretty good ethical razor for specific acts.
>> "Is it consciousness—phenomenal experience—that's really being evaluated in these theories?"
I don't think it's something that was ever very well thought out. The notion dates back to the early 20th century, and I think they took consciousness as kind of given. It was an attempt to explain the great mystery of wavefunction collapse. The mystery remains, but few, I think, believe that consciousness is a required element.
"Conceptually" might be the the wrong word. I meant that the reality uncovered through our math has begun to defy our intuitions. Possibly this has something to do with imaginary numbers (I once wrote an Idle Speculation about that). The square root of a negative number is inconceivable, in the same way that being outside space or time is inconceivable. And yet if you look into modern physics, you find things that appear to be outside space and time as we understand it -- things that aren't anywhere in particular, that do not exist at any particular time, that confound and frustrate our intuitions of the way the universe and its contents are supposed to behave.
It's so bad that for a long time, physicists took refuge in a "shut up and calculate" mode. The impressive thing is that the calculations worked. We appeared to be dealing with a reality that hung together in some important way, but of which we could form no intuitive conception. Calling the math "nonsensical" isn't really fair. What it says may seem nonsensical, but what it does is deeply persuasive.
To me this sounds a lot like some sort of window on a noumenal world. The question then is what we mean when we call it "inaccessible." Does being able to manage it using extremely abstruse and indirect methods count as "access," even though we are doomed to draw a blank on the phenomenology?
This comment went into the wrong place. Sorry about that. Substack has me thoroughly confused and about ready to throw something.
It looks like the right place to me, but maybe not where you meant it to go? Anyway, no worries, and I'm sorry Substack is such a pain. I think it's even more difficult coming from Wordpress. I get annoyed by the lack of formatting features that we're used to at WP.
I tried to comment without being signed in, thinking that a sign-in would be offered as part of the attempt. This theory was half-right. Substack seemed to offer a sign-in, but after I identified myself, it still didn't post the comment. It just kept asking me to sign in again, with the same dialog box. Eventually I twigged that I had to go and sign into Substack elsewhere before I could comment. Yelling "Just post the comment, you stupid f*&%ing thing!" didn't seem to be helping.
That's weird. I never have to sign in. Maybe that's because I never sign out? Well I'm sorry Substack is so annoying. I've noticed weird little glitches with it on other things. Funny that yelling didn't help. That usually does the trick for me!
Is there a reality independent of mind? We can only know anything with our minds. Then it is truly baffling to say we can know mind-independent reality.
I believe this puzzle can be solved only by enquiring into the nature of knowledge itself. <a href="http://shajanmathew.com/2023/11/01/3-what-is-knowledge/">What does it mean to ‘know’ something?</a> Such an enquiry will eventually lead us to conclude fundamental reality is neither material nor mental. It can only be described as unknowable 'nature-in-itself’.
I looked at the Nagel book at Amazon, and it's $31.49 for the Kindle version (more for paperback and almost $75 for hardcover). So, I don't think I'll get it anytime soon. I did buy /Mind, Language And Society/, by John Searle, and so far am really enjoying it (just read the first section so far). It's in large part his defense of external realism and a critique of idealism.
I cracked up when I read this bit:
"Famous examples [of what he views as philosophically weak arguments] are David Hume’s refutation of the idea that causation is a real relation between events in the world, Bishop George Berkeley’s refutation of the view that a material world exists independently of our perceptions of it, and the rejection by Descartes, as well as many other philosophers, of the view that we can have direct perceptual knowledge of the world."
So, he's way on my wavelength! :)
It's funny that the book is still so expensive. There was a receipt in my husband's copy, which he bought in the 90s, and I was surprised that he paid 20 bucks for it that long ago (and then clearly didn't read it).
Here's a short paper by Searle, in case anyone's interested:
https://faculty.wcas.northwestern.edu/paller/dialogue/propertydualism.pdf
I think I prefer Nagel, but I haven't read any of Searle's books, so it's hard to say.
What does he say about Hume and causality?
I haven't gotten to a part where he specifically argues against Hume, but in the chapter "Skepticism, Knowledge, and Reality" he says that most Idealist arguments depend on illusion or science (the latter being most common these days).
Illusion arguments boil down the impossibility of distinguishing what he calls the veridical case versus "illusions, hallucinations, delusions and so on." He goes on to say, "The simplest version that I know of is to be found in Hume. He thought that naive perceptual realism was so easily refutable that he dismissed it in a few sentences." One example is, that if you cross your eyes, you see double, but this doesn't mean the *world* doubled. Since we can't trust these perceptions to be veridical, or distinguish them from false perceptions, we can't trust our perceptions. He argues:
"But why should a single experience be all I have to go on? [...] Any single experience only makes the kind of sense to me that it does because it is part of a network of other experiences, and it goes on against a Background of taken-for-granted capacities I have for coping with the world. If that is right, then the single experience, considered in isolation by itself, is not sufficient to make the distinction between veridical perception and hallucination."
Which is very similar to what I've argued about external realism. Individual cases cannot be the basis for our analysis of how reality works. Our understanding of reality is a consensus that is convergent (and contingent). Our ability to manipulate and predict physical behavior, as well as its consistency and universality, strongly support external realism.
The science argument against realism is essentially what Kant said about transcendental idealism -- all we can know are phenomena through the mechanism of our senses, and we can know *nothing* about noumena. But that we can give an accurate and testable account of *how* those senses produce phenomena argues to the reality of noumena and does tell us *something* about them. (As I've said before, I think we get a "wireframe" view of reality that misses much but is not entirely inaccurate. That we can successfully navigate a persistent reality says something about that reality.)
From a modern physics perspective, Hume's rejection of causality is especially weak. In the three centuries since Hume, we have developed a very good understanding of it, including things like light cones which limit what can cause something (it must be in the past light cone), as well as an understanding of particle physics -- causality at its most fundamental level.
I liked the paper you linked to. It's a pretty good answer the question of epiphenomenalism. As I think you know, I have spiritual suspicions, but those are on the faith and belief side. On the physical side, I quite agree with Searle about consciousness. It's an emergent property of the brain, but not distinct from it.
Oh, I forgot to say, you should check and see if it's available at your library. If not, you could request it. He's a pretty dang famous philosopher, so I would think they'd honor that request.
I did, and the only book of his they have (as an ebook) is /Mind and Cosmos/. Which I've placed on hold!