Blogs / Cosmic Variance

Dana McCourt at The Edge of the American West has a short series of posts on Leibniz and Spinoza, based partly on The Courtier and the Heretic by Matthew Stewart. This is great stuff, the kind of thing blogs do better than anything — bite-sized interesting pieces that stand by themselves, just because. (And the cheap chronological hook that November 18 was the day in 1676 when the two met in the Hague.)

All noble things are as difficult as they are rare.

The best of all possible worlds.

Why should we be loyal to reason if it pushes us into the abyss?

Scientists think of Leibniz as Newton’s rival in inventing calculus, and barely think of Spinoza at all. But they were both among the most influential philosophers of all time.

Leibniz published books and treatises, but much of what we know of his philosophy comes in the form of letters. I’ve joked that he invented the calculus on the back of a cocktail napkin in the corporate lounge while his flight from Paris to Hanover was delayed, and that of course was an exaggeration for comic effect.

It wasn’t the calculus, but a dialogue on theology, and it was on a yacht from London to Rotterdam that was held fast in port by headwinds.

The two men came started from different launching points, but ended up arriving at very similar philosophies.

Spinoza’s naturalism lead him to atheism, but Leibniz came to Spinoza via his theism. That is, Leibniz found himself desperately trying to come up with an argument that showed that his own philosophy was not threatened by the spectre of Spinozism, but his philosophical commitments, especially those concerning the nature of God, meant his options were limited.

Foremost among those commitments was the Principle of Sufficient Reason: the idea that nothing is “just because,” there is always an intelligible reason for everything feature of the world. It sounds innocent enough, but takes you to dangerous places if you buy into it with all your heart.

As far as I can tell, the PSR is not especially popular in respectable philosophical circles these days, but it is still hanging in there. It’s basically the foundation for Paul Davies’s claim that any respectable laws of physics must have a good reason for being the way they are. I don’t agree, myself; it might be true, but I’m very open to the possibility that the final product of our investigation into the ultimate workings of nature will be a set of rules that could easily have been different, but they simply are they way they are. At the very least, I would strongly defend the proposition that we should be open to this possibility; whether or not there is a small set of brute facts about the universe that lack any underlying justification, there is certainly no good reason to deny that scenario on the basis of pure thought, before we know what the ultimate rules actually are.

At a more casual level, the PSR shows up in the common belief that everything happens for a reason. That’s where the pernicious side of this purportedly sunny philosophy rears its head: if everything has a purpose, even the most terrible random events require an explanation, and from there it’s a short road to the urge to put the blame on someone. Or, on the flip side, to kill ‘em all and let God sort them out. One day, when human beings have universally adopted an enlightened materialist view of the cosmos and have developed a corresponding system of ethics and morality, an important piece of the puzzle will be an acceptance of randomness and contingency. All is not for the best, in the best of all possible worlds, and that leaves it up to us to try to make things better.

Among other important elections, on November 4 Californians will be voting on Proposition 8, a measure to amend the state Constitution in order to ban same-sex marriages. The polling has been very close, with a possible late break toward a “Yes” vote; this would effectively overturn a California Supreme Court decision from this May that held that same-sex couples had a right to marry under the equal protection clause of the California Constitution. Eventually, of course, gay marriage will be accepted throughout the country, and we will look back on today as the bad old days of discrimination. But that’s cold comfort to the couples who would like to celebrate their love for each other right now. You can donate and learn more about the measure at No On 8.

We are occasionally asked why a Physics Blog spends time talking about religion and politics and all that nonsense. A perfectly correct answer is that this is not a Physics Blog, it’s a blog by some people who happen to be physicists, and we talk about things that interest us, blah blah blah. But there is another, somewhat deeper, answer. Physics is not just a technical pastime played with numerical simulations and Feynman diagrams; nor is it a purely instrumental technique for unlocking Nature’s secrets so as to build better TV sets. Physics, as it is currently practiced, is a paradigm for a naturalistic way of understanding the world. And that’s a worldview that has consequences stretching far beyond the search for the Higgs boson.

Charles Taylor makes an admirable stab at a very difficult task: understanding the premodern mindset from our modern vantage point. (Via 3 Quarks Daily.) There are many ways in which our perspective differs from that of someone living five hundred years ago in a pre-scientific age, but Taylor emphasizes one important one:

Almost everyone can agree that one of the big differences between us and our ancestors of five hundred years ago is that they lived in an “enchanted” world, and we do not; at the very least, we live in a much less “enchanted” world. We might think of this as our having “lost” a number of beliefs and the practices which they made possible. But more, the enchanted world was one in which these forces could cross a porous boundary and shape our lives, psychic and physical. One of the big differences between us and them is that we live with a much firmer sense of the boundary between self and other. We are “buffered” selves. We have changed.

Our ancestors lived in an enchanted world, where the boundary between the physical and the moral and the spiritual was not very clearly drawn. It made perfect sense, at the time, to attribute to the external world the same kinds of meanings and impulses that one found in the human world — purposes, consciousnesses, moral judgments. One of the great accomplishments of modernity was to construct a new way of understanding the world — one based on understandable, formal rules. These days we understand that the world is not magic.

This change in perspective has led to extraordinary changes in how we live, including the technology on which we are sharing these words. But the consequences go enormously deeper than that, and it is no exaggeration to say that our society has still not come fully to grips with the ramifications of understanding the world around us as fundamentally natural and rules-based. That’s the point at which the worldview suggested by science has had a profound effect on moral reasoning.

For our present purposes, the most important consequence is this: notions of “right” and “wrong” are not located out there in the world, waiting to be discovered, in the same sense that a new kind of elementary particle (or even a new law of physics) is located out there in the world. Right and wrong aren’t parts of the fundamental description of reality. That description has to do with wave functions and Hamiltonian dynamics, not with ethical principles. That is what the world is made of, at a deep level. Everything else — morality, love, aesthetics — is up to us.

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Robert Novak, conservative pundit/journalist and TV personality, is retiring after being diagnosed with a brain tumor. Novak and I probably don’t agree on many things, and he isn’t called “The Prince of Darkness” for nothing (nor does he seem to especially mind). But brain tumors shouldn’t happen to anyone, so perhaps this is the place to share my Novak story.

Last September I gave a talk at a somewhat unusual venue: a conference at the University of Illinois on “Plato’s Timaeus Today.” Most of the speakers and attendees, as you might expect, were philosophers or classicists interested in this particular Platonic dialogue — which, apparently, used to be one of his most popular back in the Middle Ages, although it’s fallen a bit out of favor since then. But one of the central purposes of the Timaeus (full text here) was to explain Plato’s theory of the origin of the universe. (Briefly: the demiurge did it, not from scratch, but by imposing order on chaos.) (Also! This dialogue is the origin of the myth of Atlantis. It was not, as far as anyone can tell, a pre-existing story; Plato just made it up.) So the organizers thought it would be fun to invite a physicist or two, to talk about how we think about the universe these days. Sir Tony Leggett gave a keynote address, and I gave a talk during the regular sessions.

The point of my talk was: Plato was wrong. In particular, you don’t need an external agent to create the universe, nor to impose order on the chaos. These days we are reaching toward an understanding of the entire history of the universe in which there is nothing other than the laws of physics working themselves out — a self-contained, complete, purely materialist conception of the cosmos. Not to say that we have such a theory in its full glory, obviously, but we see no obstacles and are making interesting progress. See here and here for more physics background.

And there, during my talk, sitting in the audience, was none other than Robert Novak. This was a slight surprise, although not completely so; Novak was a UIUC alumnus, and was listed as a donor to the conference. But he hadn’t attended most of the other talks, as far as I could tell. In any event, he sat there quietly in his orange and navy blue rep tie, and I gave my talk. Which people seemed to like, although by dint of unfortunate scheduling it was at the very end of the conference and I had a plane to catch so had to run away.

And there, as I was waiting at the gate in the tiny local airport, up walks Robert Novak. He introduced himself, and mentioned that he had heard my talk, and had a question that he was reluctant to ask during the conference — he didn’t want to be a disruption among the assembled academics who were trying to have a scholarly conversation. And I think he meant that sincerely, for which I give him a lot of credit. And I give him even more credit for taking time on a weekend to zip down to Urbana (from Chicago, I presume) to listen to some talks on Plato. Overall, the world would be a better place if more people went to philosophy talks in their spare time.

Novak’s question was this: had I discussed the ideas I had talked about in my presentation with any Catholic theologians? The simple answer was “not very much”; I have talked to various theologians, many of them Catholic, about all sorts of things, but not usually specifically about the possibility of an eternally-existing law-abiding materialist universe. The connection is clear, of course; one traditional role of religion has been to help explain where the world came from, and one traditional justification for the necessity of God has been the need for a Creator. (Not the only one, in either case.) So if science can handle that task all by itself, it certainly has implications for a certain strand of natural theology.

Understanding that it was not an idle question (and that Novak is a Catholic), I added my standard admonition when asked about the theological implications of cosmology by people who don’t really want to be subjected to a full-blown argument for atheism: whether you want to believe in God or not, it’s a bad idea to base your belief in God on an urge to explain features of the natural world, including its creation and existence. Because eventually, science will get there and take care of that stuff, and then where are you?

And, once again to his credit, Novak seemed to appreciate my point, whether or not he actually agreed. He nodded in comprehension, thanked me again for the talk, and settled down to wait for his flight.

I’m sure Ruben Bolling is making fun of people I disagree with, and not of me.

The underlying point is a good one, though, and one that is surprisingly hard for people thinking about cosmology to take to heart: without actually looking at it, there is no sensible a priori reasoning that can lead us to reliable knowledge about parts of the universe we haven’t observed. Einstein and Wheeler believed that the universe was closed and would someday recollapse, because a universe that was finite in time felt right to them. The universe doesn’t care what feels right, or what “we just can’t imagine”; so all possibilities should remain on the table.

On the other hand, that doesn’t mean we can’t draw reasonable a posteriori conclusions about the unobservable universe, if the stars align just right. That is, if we had a comprehensive theory of physics and cosmology that successfully passed a barrage of empirical tests here in the universe we do observe, and made unambiguous predictions for the universe that we don’t, it would not be crazy to take those predictions seriously.

We don’t have that theory yet, but we’re working on it. (Where “we” means an extremely tiny fraction of working scientists, who receive an extremely disproportionate amount of attention.)

Science, that is. No, this is not what I have in mind. Rather, this provocative statement — the discoveries of science should be disturbing, they shouldn’t simply provide gentle reassurance about our place in the universe — is the conclusion reached by my latest Bloggingheads dialogue, with David Albert.

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David is a philosopher of science at Columbia, author of Time and Chance as well as Quantum Mechanics and Experience. We talked about what philosophers of science do, the awful What the Bleep Do We Know? movie, string theory and falsifiability, and touched on time before running out thereof. Future episodes are clearly called for.

Lurking behind the debate over the high energy physics budget is a meta question that rarely gets addressed head-on: in a world with many things that we would like to do, but limited resources to do them, how do we decide what questions are interesting enough to warrant our attention? This question arises at every level. If we have a certain number of dollars to spend on particle physics, how much should go to the high-energy frontier and how much to smaller-scale experiments? Within fundamental science, how much should go to physics and how much to biology or astronomy or whatever? And it’s not just money: within a university, how many faculty positions should go to historians, and how many to archaeologists? Within philosophy, how many logicians do we need, and how many ethicists? It’s not even an especially academic question: which book am I going to bring with me to read on the plane?

There are a number of issues that get tied up in such considerations. One is that certain activities simply require certain resources, so if we judge them sufficiently interesting to be pursued then we need to be prepared to devote the appropriate resources their way. A colleague of mine in condensed-matter physics was fond of complaining about all the great small-scale physics that his community could do if they only had half of Fermilab’s budget. Which is undoubtedly true, but with half of Fermilab’s budget you wouldn’t get half the science out of Fermilab — you wouldn’t get anything at all. If that kind of particle physics is worth doing at all (which is a completely fair question), there is an entry fee you can’t avoid paying.

But more deeply, the problem is that there is no intrinsic property of “interestingness” that we can compare across different academic questions. Questions are not interesting in and of themselves; they are interesting to somebody. If I happen to not be interested in the American Civil War, and a friend of mine thinks it’s fascinating, that doesn’t mean that one of us is “right” and the other “wrong”; it just means that we have different opinions about the interestingness of that particular subject. It’s precisely the same kind of personal decision that goes into preferences for different kinds of music or cuisine. The difference is that, unlike CD’s or appetizers, we don’t consume these goods individually; we need to make some collective decision about how to allocate our intellectual resources.

People pretend that there are objective criteria, of course. The standard battle lines within physics are drawn between research that is “fundamental” and research that is “useful.” I was once in the audience for a colloquium by Steven Weinberg, back in the days when we were still planning on the Superconducting Supercollider, and he was talking about why particle physics was worthy of substantial investment: “People sometimes object to the way we speak about particle physics, objecting that we give the impression that it’s more `fundamental’ than other fields. But I think it’s okay, because … well, it is more fundamental.” Contrariwise, I’ve heard condensed-matter physicists wonder with a straight face why anyone in the general public would be interested in books on string theory and cosmology. After all, those subjects have no impact at all on their everyday lives, so what is the possible interest?

In reality, there is no objective metaphysical standard to separate the interesting from the uninteresting. There are a bunch of human beings with different interests, and we have the social task of balancing them. A complication arises in the context of academia, where we don’t weigh everyone’s interests equally — there are experts whose opinions count for more than those on the streets. And that makes sense; even if I have no idea which directions in contemporary chemistry or French literature are interesting, I am more than willing to leave such questions in the hands of people who care deeply and have contributed to the fields.

The real problem, of course, is that sometimes we have to compare between fields, so that decisions have to be made by people who are almost certainly not experts in all of the competing interests. We have, for example, the danger of self-perpetuation, where a small cadre of experts in an esoteric area continue to insist on the importance of their work. That’s where it becomes crucial to be able to explain to outsiders why certain questions truly are interesting, even if the outsiders can’t appreciate all the details. In fundamental physics, we actually have a relatively easy time of it, our fondness for kvetching notwithstanding; it’s not too hard to appreciate the importance of concepts like “the laws of nature” and “the beginning of the universe,” even to people who don’t follow the math. Making a convincing request for a billion dollars is, of course, a different story.

Sadly, none of these high-minded considerations are really at work in the current budget debacle. High-energy physics seems to be caught in a pissing match between the political parties, each of whom wants to paint the other as irresponsible.

The White House and congressional leaders exchanged barbs Tuesday over who was to blame for the Fermilab impasse. Lawmakers said the Bush administration’s tight overall budget targets tied their hands, while a spokesman for Bush’s Office of Management and Budget said the Democratic leaders could have met the targets by cutting back on other discretionary elements of the budget.

Durbin said the $196 billion required for the wars in Iraq and Afghanistan left little room for budget maneuvering.

“We were left with stark choices: reduce funding for high-end physics or cut money for veterans; reduce spending at Fermilab or eliminate funding for rural hospitals,” Durbin said in a statement Tuesday.

Sean Kevelighan, a spokesman for the administration’s Office of Management and Budget, said Congress could have chosen instead to take more money from the $9.7 billion worth of earmarks designated for lawmakers’ projects.

“The choices were up to the Congress,” Kevelighan said.

As annoying as academia can be, politics is infinitely worse.

Paul Davies has published an Op-Ed in the New York Times, about science and faith. Edge has put together a set of responses — by Jerry Coyne, Nathan Myhrvold, Lawrence Krauss, Scott Atran, Jeremy Bernstein, and me, so that’s some pretty lofty company I’m hob-nobbing with. Astonishingly, bloggers have also weighed in: among my regular reads, we find responses from Dr. Free-Ride, PZ, and The Quantum Pontiff. (Bloggers have much more colorful monikers than respectable folk.) Peter Woit blames string theory.

I post about this only with some reluctance, as I fear the resulting conversation is very likely to lower the average wisdom of the human race. Davies manages to hit a number of hot buttons right up front — claiming that both science and religion rely on faith (I don’t think there is any useful definition of the word “faith” in which that is true), and mentioning in passing something vague about the multiverse. All of which obscures what I think is his real point, which only pokes through clearly at the end — a claim to the effect that the laws of nature themselves require an explanation, and that explanation can’t come from the outside.

Personally I find this claim either vacuous or incorrect. Does it mean that the laws of physics are somehow inevitable? I don’t think that they are, and if they were I don’t think it would count as much of an “explanation,” but your mileage may vary. More importantly, we just don’t have the right to make deep proclamations about the laws of nature ahead of time — it’s our job to figure out what they are, and then deal with it. Maybe they come along with some self-justifying “explanation,” maybe they don’t. Maybe they’re totally random. We will hopefully discover the answer by doing science, but we won’t make progress by setting down demands ahead of time.

So I don’t know what it could possibly mean, and that’s what I argued in my response. Paul very kindly emailed me after reading my piece, and — not to be too ungenerous about it, I hope — suggested that I would have to read his book.

My piece is below the fold. The Edge discussion is interesting, too. But if you feel your IQ being lowered by long paragraphs on the nature of “faith” that don’t ever quite bother to give precise definitions and stick to them, don’t blame me.

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The best talk I heard at the International Congress of Logic Methodology and Philosophy of Science in Beijing was, somewhat to my surprise, the Presidential Address by Adolf Grünbaum. I wasn’t expecting much, as the genre of Presidential Addresses by Octogenarian Philosophers is not one noted for its moments of soaring rhetoric. I recognized Grünbaum’s name as a philosopher of science, but didn’t really know anything about his work. Had I known that he has recently been specializing in critiques of theism from a scientific viewpoint (with titles like “The Poverty of Theistic Cosmology“), I might have been more optimistic.

Grünbaum addressed a famous and simple question: “Why is there something rather than nothing?” He called it the Primordial Existential Question, or PEQ for short. (Philosophers are up there with NASA officials when it comes to a weakness for acronyms.) Stated in that form, the question can be traced at least back to Leibniz in his 1697 essay “On the Ultimate Origin of Things,” although it’s been recently championed by Oxford philosopher Richard Swinburne.

The correct answer to this question is stated right off the bat in the Stanford Encyclopedia of Philosophy: “Well, why not?” But we have to dress it up to make it a bit more philosophical. First, we would only even consider this an interesting question if there were some reasonable argument in favor of nothingness over existence. As Grünbaum traces it out, Leibniz’s original claim was that nothingness was “spontaneous,” whereas an existing universe required a bit of work to achieve. Swinburne has sharpened this a bit, claiming that nothingness is uniquely “natural,” because it is necessarily simpler than any particular universe. Both of them use this sort of logic to undergird an argument for the existence of God: if nothingness is somehow more natural or likely than existence, and yet here we are, it must be because God willed it to be so.

I can’t do justice to Grünbaum’s takedown of this position, which was quite careful and well-informed. But the basic idea is straightforward enough. When we talk about things being “natural” or “spontaneous,” we do so on the basis of our experience in this world. This experience equips us with a certain notion of natural — theories are naturally if they are simple and not finely-tuned, configurations are natural if they aren’t inexplicably low-entropy.

But our experience with the world in which we actually live tells us nothing whatsoever about whether certain possible universes are “natural” or not. In particular, nothing in science, logic, or philosophy provides any evidence for the claim that simple universes are “preferred” (whatever that could possibly mean). We only have experience with one universe; there is no ensemble from which it is chosen, on which we could define a measure to quantify degrees of probability. Who is to say whether a universe described by the non-perturbative completion of superstring theory is likelier or less likely than, for example, a universe described by a Rule 110 cellular automaton?

It’s easy to get tricked into thinking that simplicity is somehow preferable. After all, Occam’s Razor exhorts us to stick to simple explanations. But that’s a way to compare different explanations that equivalently account for the same sets of facts; comparing different sets of possible underlying rules for the universe is a different kettle of fish entirely. And, to be honest, it’s true that most working physicists have a hope (or a prejudice) that the principles underlying our universe are in fact pretty simple. But that’s simply an expression of our selfish desire, not a philosophical precondition on the space of possible universes. When it comes to the actual universe, ultimately we’ll just have to take what we get.

Finally, we physicists sometimes muddy the waters by talking about “multiple universes” or “the multiverse.” These days, the vast majority of such mentions refer not to actual other universes, but to different parts of our universe, causally inaccessible from ours and perhaps governed by different low-energy laws of physics (but the same deep-down ones). In that case there may actually be an ensemble of local regions, and perhaps even some sensibly-defined measure on them. But they’re all part of one big happy universe. Comparing the single multiverse in which we live to a universe with completely different deep-down laws of physics, or with different values for such basic attributes as “existence,” is something on which string theory and cosmology are utterly silent.

Ultimately, the problem is that the question — “Why is there something rather than nothing?” — doesn’t make any sense. What kind of answer could possibly count as satisfying? What could a claim like “The most natural universe is one that doesn’t exist” possibly mean? As often happens, we are led astray by imagining that we can apply the kinds of language we use in talking about contingent pieces of the world around us to the universe as a whole. It makes sense to ask why this blog exists, rather than some other blog; but there is no external vantage point from which we can compare the relatively likelihood of different modes of existence for the universe.

So the universe exists, and we know of no good reason to be surprised by that fact. I will hereby admit that, when I was a kid (maybe about ten or twelve years old? don’t remember precisely) I actually used to worry about the Primordial Existential Question. That was when I had first started reading about physics and cosmology, and knew enough about the Big Bang to contemplate how amazing it was that we knew anything about the early universe. But then I would eventually hit upon the question of “What if they universe didn’t exist at all?”, and I would get legitimately frightened. (Some kids are scared by clowns, some by existential questions.) So in one sense, my entire career as a physical cosmologist has just been one giant defense mechanism.

Via Mixing Memory, Slate has a collection of short reminisces about Richard Rorty by everyone from Brian Eno to Jurgen Habermas. (Although, admittedly, I sometimes have trouble telling the two apart.) In one contribution, semi-retired blogger of leisure Michael Bérubé says just what I was saying, except from a better-informed and more eloquent perspective.

In the spring of 1985, when I was a graduate student at the University of Virginia, Richard Rorty’s seminar on Martin Heidegger changed my life. Not because he converted me to Heidegger; he was not much of a Heidegger fan himself. But his seminar introduced me to anti-foundationalist pragmatism — to the idea that our beliefs, our vocabularies, and our ways of life are contingent. “Um, contingent on what?” I asked. “Not contingent on anything,” Rorty replied, “just — contingent.”

Although I was never quite convinced by Rorty’s claims that the languages of the physical sciences were as contingent as any other form of language, I was thoroughly convinced, by the end of the term, that it was a bad idea to think of philosophy as a kind of epistemological physics, in which moral truths are waiting somewhere out there to be discovered, like planets or particles. One of the reasons Rorty’s view of the world seemed so attractive was that it offered us humans a useful way to think about why it is that we disagree with each other about what those moral truths actually are: If you think you are acting in accordance with the eternal moral truths of the universe, after all, it is likely that you will think of people who think and act differently as being defective, deluded, or downright dangerous. On the other hand, if you think that morality is a matter of contingent vocabularies, you don’t have to become a shallow relativist — you can go right on believing what you believe, except that you have to give up the conviction that there’s no plausible way another rational person could think differently.

Richard Rorty has passed away. He was arguably the most well-known living American philosopher, not least of which because he was a wonderful communicator; see Jacob Levy’s appreciation of his rhetorical skills.

Intellectually, Rorty was hard to pin down; while he was most closely identified with the American pragmatist tradition of Dewey and Peirce, he was trained as a hard-core analytic philosopher, and later became heavily influenced both by Wittgenstein and by continental/”postmodern” philosophy. So he managed to annoy everybody, basically. But his real project was to take seriously radical critiques of meaning and truth while simultaneously offering a positive prospect for morality and human living. Which is a good project to have, I think.

Wikipedia has a representative quote from Contingency, Irony, and Solidarity, in which Rorty spells out his view of a good “ironist”:

(1) She has radical and continuing doubts about the final vocabulary she currently uses, because she has been impressed by other vocabularies, vocabularies taken as final by people or books she has encountered; (2) she realizes that argument phrased in her present vocabulary can neither underwrite nor dissolve these doubts; (3) insofar as she philosophizes about her situation, she does not think that her vocabulary is closer to reality than others, that it is in touch with a power not herself.

As physicists go, I’m more sympathetic to postmodernism than most. (Who are, you know, not very sympathetic.) What I really think is that people who think carefully about science and people who think carefully about the social construction of truth would have a lot to learn from each other, if they would approach each other’s concerns and insights in good faith, which is hard to do.

When Rorty talks about “final vocabularies” in the quote above, he’s not really thinking of “quantum field theory” or “general relativity” or even “the scientific method,” although they would arguably be legitimate examples. He’s thinking of doctrines of religion or morality or politics or ethics or aesthetics that we use to judge good and bad and right and wrong in our lives. These are areas in which such vocabularies truly are contingent, and unpacking our presuppositions about their finality is a useful practice.

Science is different. To do science, we presume the existence of a “real world” that is “out there” and follows a set of rules and patterns that are completely independent of whatever actions we humans may be taking, including our actions of conceptualizing that real world. Questions of good and bad and right and wrong are not like that; their subject matter is our judgments themselves, which are subject to interrogation and ultimately to alteration. Right and wrong are not out there in the world to be probed and described; we create them through various human mechanisms. A scientist cannot consistently hold radical doubts about the nature of the real world.

On the other hand — and this is the part that, I think, scientists consistently miss — we certainly can hold radical doubts about the vocabulary with which we as scientists describe that real world. In fact, when pressed in other contexts, we are the first to insist that scientific theories are always useful but limited approximations, capturing some part of reality but certainly not the whole. Furthermore, even experimental data do not provide any unmediated glimpse of reality; not only are there error bars, but there are also the irreducible theory-laden choices about which data to collect, and how to fit them into our frameworks. These are commonplace scientific truisms, but they are also deep postmodern insights.

In my personal intellectual utopia, postmodernists would appreciate how science differs from morality and ethics and aesthetics by the ontological independence of its subject matter, while scientists would appreciate how there is a lot we have yet to quite understand about how we use language and evidence in an ultimately contingent way. Just as Rorty wanted to make ironic skepticism compatible with human solidarity, I’d like to see suspicion toward final vocabularies made compatible with the undeniable truth of scientific progress.

Or am I just being ironic?

More: Mixing Memory has a list of other blog posts on Rorty; Continental Philosophy has a collection of links and a recent video.