Defending Thomas Kuhn from Errol Morris

Errol Morris' series on Thomas Kuhn started amusingly: it was fun to hear that Morris -- the director of great documentary The Fog of War -- was actually a first-year graduate student in the History of Science program at Princeton (and rejected by Harvard's History of Science department!).  (I don't know, that gave me quite a kick.)  And it was funny to hear that he and Thomas Kuhn hadn't gotten along, that Kuhn had thrown an ash-tray at him because he refused to give up his Whiggish ways of doing the history of science.  (There's probably some poetic license here, but it's still funny!)

But as the story progressed (parts two, three, four, five), my enjoyment started to wane.  It wasn't the flowing, free-associative style, which was still fun, although I really didn't see what the digressions into the Pythogorean society had to do with the concept of incommensurability.  No, it was the intellectual portrayal of Thomas Kuhn.  If one reads Morris without reading Kuhn, then Kuhn comes across as an idiot.  And all of us who found The Structure of Scientific Revolutions useful come across as either idiots or fashionable post-modernists who like Structure because it fits in with the relativistic fashions of the day.

What is Morris' problem with Kuhn (other than that he clearly didn't like him)?  Two things.  First, he argues that the concept of incommensurability is incoherent.  And second, that it opens the doors to all sorts of relativism.  The second point is old hat.  Much ink has been shed on how if we give up the idea of Truth, of an unmediated reality out there that we are accountable to, then we are on a slippery slope to ethical relativism.  That it leaves us without a reply to totalitarian dictatorships, that it leaves the door open to the O'Briens of the world who want us to believe that 2+2=5.  Etc.  The first point is old hat too.  As John Holbo points out, incommensurability was criticized in just this way even when Structure was published.  The idea here is that if two paradigms are incommensurable, then we have no way of doing the history of science; so the fact that Kuhn himself could understand the older paradigms proves that paradigms are not really incommensurable.  

As fields, the history of science, and Science and Technology Studies (STS) have moved on: the idea of a linguistic conceptual framework that under-girds scientific theories has been replaced by a search for material practices that constitute science.  Kuhn is studied less as someone who offered fresh new insights but as one of  the oldies: routinely grouped together with Popper, Feyerabend and Lakatos.  (I also think that while Kuhn makes several missteps in Structure -- he tries to define incommensurability linguistically, he starts to talk about using computer programs to understand incommensurability -- the idea of science as being constituted by material practice is there in the book.  As are other things that we now look for as STS scholars: the practices of pedagogy and training in science, the incentive structure, etc.) 


Still.  I'd like to offer a defense of Kuhn and of Structure and why the criticisms that Morris offers are mistaken.  Reading Structure was a transforming experience for me -- and I'd like to bring out why. 

So without any further ado, here goes.

Kuhn's book is more heard about and talked about than read.  For example, I knew (or thought I knew) the fundamentals of its argument long before I read it.  That argument goes something like this:

• That scientific advances happen not cumulatively, but in bursts -- conceptual revolutions alternating with periods of "normal" science
• That  underlying all scientific theories is something called a "paradigm" (think of it as some kind of underlying conceptual scheme) and that one paradigm gets replaced by another during a scientific revolution.  
• And finally, when paradigms change, when a new paradigm replaces the old one, the two are incommensurable, so that when scientists argue for the merits of either paradigm, they are essentially talking past each other.  The paradigm that wins out wins not because it is true.  

The key thing to understand here is that most people would be fine with this argument if it wasn't for the incommensurability part.  Here, for instance, is Thomas Nagel, reviewing Alan Sokal's Fashionable Nonsense:

Much of what Kuhn says about great theoretical shifts, and the inertial role of long-established scientific paradigms and their cultural entrenchment in resisting recalcitrant evidence until it becomes overwhelming, is entirely reasonable, but it is also entirely compatible with the conception of science as seeking, and sometimes finding, objective truth about the world. What has made him a relativist hero is the addition of provocative remarks to the effect that Newton and Einstein, or Ptolemy and Galileo, live in "different worlds," that the paradigms of different scientific periods are "incommensurable," and that it is a mistake to think of the progress of science over time as bringing us closer to the truth about how the world really is.

Before I read Structure, I pretty much agreed with this.  (How could I not?)

When I did read Structure, however, I realized that while this summary was not wrong, the book said a great many other things.  I realized that: 

That Kuhn is not doing philosophy of science, despite the fact that he's almost universally known as a philosopher of science.  It's true that Structure makes a series of bold, philosophical claims.  But it also tries to back them up with historical evidence -- not by using anecdotes but with the kind of concrete, archival research that historians do.  Analytic philosophy, on the other hand, is not an empirical field.  The subject it resembles the most is pure mathematics: you solve "problems" (the problem of knowledge, of skepticism), you use symbolic logic, you use paper and pencil, you construct proofs and thought experiments.  But you do NOT collect data of any sort, you do not make hypotheses that you then hope to confirm by looking at the data.  Kuhn was grounded in the history of science, the theory of scientific change that he propounded came from his close study of early modern science. (Although, as Ian Hacking points out, very few historians of science mix history and philosophy in quite the way Kuhn did -- which is probably why he is more known as a philosopher than as a historian.)

That the biggest claim in Structure -- one that usually flies under the radar -- is not the concept of scientific paradigms, even though much space is spent talking about paradigm changes.  No.  Rather, the central aspect of science, according to Structure, is that the activity that doing science most resembles is solving puzzles.   Kuhn calls this puzzle-solving activity "normal science."  We need to understand the claim here: the point is not to denigrate scientific activity.  The point is that puzzle-solving is not usually understood as a search for knowledge.  So even if science, understood as a collective activity, is engaged in a search for knowledge, in actual concrete terms, this search for knowledge gets done by building and solving puzzles.  Now, to an extent, constructing and solving puzzles is part of all knowledge fields.  Kuhn's point though is that nowhere is this reduction of knowledge into puzzles as prevalent or as polished as in the sciences.  (This is related to how a scientific community is structured as well as its pedagogical practices.)

Finally, the paradigm is not just a linguistic conceptual scheme.  This is the mistake that interlocutors like Morris make.  They think that a paradigm and incommensurability are philosophical concepts.  They are not.  They are not even linguistic (although Kuhn sometimes talks about them that way).  They are -- and this is more important than anything else -- about practice.  My key to Structure, the moment when it all came together for me -- what a paradigm was and how it functioned.  I'm going to reproduce the full paragraph from Kuhn:

A phenomenon familiar to both students of science and historians of science provides a clue.  The former regularly report that they have read through a chapter of their text, understood it perfectly, but nonetheless had difficulty solving a number of the problems at the chapter's end.  Ordinarily, also, those difficulties dissolve in the same way.  The student dicovers, with or without the assistance of his instructor, a way to see a problem as like a problem he has already encountered.  Having seen the resemblance, grasped the analogy between two or more distinct problems, he can interrelate symbols and attach them to nature in the ways that have proved effective before.  The law-sketch, say f = ma, has functioned as a tool, informing the student what similarities to look for, signaling the gestalt in which the situation is to be seen.  The resultant ability to see a variety of situations as like each other, as subjects for f = ma or some other symbolic generalization, is, I think, the main thing a student acquires by doing exemplary problems, whether with a pencil and paper or in a well-designed laboratory.  After he has completed a certain number, which may vary widely from one individual to the next, he views the situations that confront him as a scientist in the same gestalt as other members of his specialists' group.  For him they are no longer the same situations he had encountered when his training began.  He has meanwhile assimilated a time-tested and group-licensed way of learning. (Structure, pg 189) [emphasis mine]

Believe it or not, this is exactly how it happened for me.  I studied how to draw free-body diagrams on my own, just after 10th grade.  So I had no teacher to take me step-by-step through a few solved examples, which is generally the case.  Instead, I had to read the solved examples in my textbook -- many of which struck me as incomprehensible.  I remember staring at diagrams of bodies moving on inclined planes in frustration, almost ready to cry because I didn't know what to do.  My frustration was accentuated, I think, because we had moved to a new town and I was just starting to adapt to it.

And then one day -- I am not sure how --  it went away, .  All I remember is that one fine day I found I could do free-body diagrams just fine, that in fact, I even enjoyed doing them.  Gestalt switch is probably a really good way of describing the change.  A diagram of a body on an inclined plane now means something to me that it did not before.  To use some of Kuhn's own expressions, it was as if, for me, the world had changed and while I could recall recall my frustration with how the world had looked before, I could never recapture my previous world-view; it was irretrievably lost.  Kuhn's description of paradigm shifts as gestalt switches and his talk of scientists with differnet paradigms living in "different worlds" often leads people like Morris and Nagel to call him an idealist and a relativist but I know exactly what he is talking about.

Personal remininsces aside, it's worth unpacking the paragraph in detail and making explicit all the points that Kuhn is making in it:

• A paradigm is not a set of rules.  It's more like practice, a skill, like knowing how to apply the equation f=ma to different types of scenarios (a body moving on an inclined plane, an oscillating pendulum, a body attached to a spring, etc.)   There is no way to describe in the form of rules what it means to solve problems using f=ma, you just have to learn to do it.  It's tacit knowledge, sort of like riding a bicycle.  At the same time, being able to solve problems is the only way to become a scientist.
• One has to literally go through hell to be initiated into a paradigm.  And as a matter of pedagogy, scientists have it down pat what it takes to create a competent member of their community: you teach him or her the concepts, and then you make them solve a bunch of problems.  Somewhere along the way, the student gains competence.  This authoritarian way of doing things turns away many people from doing science, but it works wonderfully well for those who like it. 
• Finally, it provides an explanation of incommensurability, of what Kuhn means when he asserts that when scientists argue over competing paradigms, they are essentially talking past each other.  Yes, if they wanted to, if they took time and effort, they could possibly understand each other.  Philosophically, incommensurability can be refuted (as Morris tries to do).  But practically, in practice, it exists.  Because learning a paradigm is a long back-breaking process, and is done usually when one is a student, established, practicing scientists have neither the time, nor the inclination, to imbibe and learn a new paradigm.   So they keep on arguing without truly understanding each other.

"But doesn't that open the door to relativism?" Morris might say.  Kuhn's answer is that the paradigm that wins out is one that the community perceives as more productive. The key word here is productive.  Scientists should feel that a certain paradigm allows them to create a rich set of problems (puzzles) that they can then solve -- which makes them prefer that paradigm.  So there is some sort of progress.  But what about the role of nature, you might ask.  Does nature play a role in the choice of a paradigm during a revolution?  The answer is yes.  And again, it goes back to the learning.  Paradigms need to be learned: by solving problems and by practicing doing experiments; nature plays a role in both of these. 

All in all, Structure taught me three things.  First, to pay attention to material practices and craft-work that are often the building blocks of any kind of scientific or engineering work.  And second, contrary to rhetoric, to pay attention to the values that often underlie scientific work.  By values, I mean things like what counts as a "good" problem, what counts as an "elegant" solution etc.  To be able to use these words successfully is to have mastered scientific practice.  Scientific knowledge can't be studied without a close understanding of the practices and values that produce it.  And finally, pedagogy is incredibly important.  Pedagogy is how a community licenses its practitioners.  How scientific practitioners are made is important if we want to understand scientific knowledge. 

I am not sure Morris will buy this defense of Kuhn.  He is an admirer of Saul Kripke, after all. 

Internal vs. External Incentives: The Case of Economics

[This is a random, off-the-cuff post, with some wild generalizations, so please let me know if you think any part of it is wrong.]

There's been an interesting debate in the blogosphere recently about what science is and whether economics is a science.  The debate is interesting not so much because it settles the issue but because it's a good data-point for looking at public understandings of what it means to do science. 

Tyler Cowen started it all off by saying:

Economics is most like a science when people do not care about the outcome of the argument.

To which Matthew Yglesias responded in agreement, adding:

In other words, social science is like science when it’s like science—disinterested. But when it’s like politics, then it’s like politics. I note that American economists are generally able to reach a much greater degree of consensus when they offer policy recommendations to foreign countries than when they offer recommendations to the US congress. That’s not because foreign countries have easier problems to solve. 

When Cowen talks about the "outcome" of the argument, he means the external outcome of the argument: in this case, specifically, the public policy that seems to be the logical consequence of a certain knowledge claim.  When a knowledge claim has no link to a public policy choice, he suggests, economics is most like a science -- a condition Yglesias calls being "disinterested."  In Ygelasias' view, when a economic knowledge claim has no obvious public policy consequences (especially for the country said economists live in), economists behave like scientists -- which is not to say that they agree, but rather, that they disagree, but in a disinterested way.

In STS, this is what I call the Internal vs. External debate on what drives science.  Do scientists accept theories because they are, in some sense, true?  Are they convinced of the validity of a certain knowledge claim because of "internal" reasons -- reasons deemed to be "proper" within the field?  Or are they influenced by what one might call "external" reasons, reasons deemed by the community to be properly out of bounds, such as the desire for money, support for a political program, etc.? 

But an interesting aspect of what it means to be a disinterested economist struck me (and correct me if I'm wrong).  As far as my reading goes, ideology doesn't count as an improper reason for being partial to a knowledge claim.  So economists will routinely proclaim that they are libertarians or progressives or egalitarians.  What they won't say is whether they are Democrats or Republicans -- and so this is often deployed in debunking someone's claim.  Thus one  is more likely to hear things like "X has nothing to say about this because he worked for a Republican president and so would rather not contradict said president's policies" rather than "So-and-so makes this claim because he is left-wing and is therefore biased"  One also hears things like (at least on blogs) "I am sympathetic to such-and-such claim because I believe in progressive causes" -- which means that ideology is arguably a more acceptable reason for being sympathetic/antagonistic to a knowledge claim, than, say, membership of a political party.

Which is, in a way, different from what counts as a proper reason for accepting a knowledge claim in the actual sciences, like physics or biology.  Here, I'd say, even ideology does not fly.  Membership of a political party, of course, is completely out of bounds.  (Note that this is an assertion about community standards and rhetoric rather than about the actual workings of the hard sciences.)

Which is to say economists should probably be comparing themselves to other social scientists rather than to the practitioners of the "hard" sciences.

Other links:

And here are two more posts about the "Is economics a science?" debate which bring out interesting rhetorical perspectives on what economists think being a science is: here and here.   Greg Mankiw's little paper on "The Macro-economist as a scientist and engineer" [PDF].  And finally, on Crooked Timber, Henry Farrell applied public choice theory to economics. 

A reply to Sam Harris

[A friend of mine enthusiastically linked to this Sam Harris piece on Facebook. I found it dreadful and philosophically incoherent, even on its own terms. I thought I'll post what I wrote about it in my email to my friend. I've tried to keep the post contained and my point is to show only that Harris point breaks down even if one accepts all his assumptions about morality.]

I was not suggesting that science can give us an evolutionary or neurobiological account of what people do in the name of "morality." Nor was I merely saying that science can help us get what we want out of life. Both of these would have been quite banal claims to make (unless one happens to doubt the truth of evolution or the mind's dependency on the brain). Rather I was suggesting that science can, in principle, help us understand what we should do and should want -- and, perforce, what other people should do and want in order to live the best lives possible. My claim is that there are right and wrong answers to moral questions, just as there are right and wrong answers to questions of physics, and such answers may one day fall within reach of the maturing sciences of the mind. As the response to my TED talk indicates, it is taboo for a scientist to think such things, much less say them in public.

Sam Harris wants not just a descriptive scientific theory of morals but a prescriptive one, a Science of Morals that helps people take moral decisions, but not just any decisions. It enables them to choose the right alternative where "right" is defined in some objective way. In other words, he says he wants to discover (or invent, or at the very least believes in the possibility of) an algorithm that helps people take the correct decision.

Now what would this algorithm be like? Are moral decisions subjective or objective?

Here Harris brings in John Searle. Searle says that subjective and objective, both of these words, have two senses, epistemological and ontological. So according to him, a scientific theory of consciousness (which doesn't exist yet) has to be epistemologically objective (meaning that the theory uses "inputs" that are accessible to any interested person) but the content of consciousness is still ontologically subjective (meaning only I have access to my states of consciousness).

So a scientific theory of morals would be like a scientific theory of consciousness: it would be epistemologically objective, meaning any interested person can get to the same conclusion if they applied it. But is the decision produced by this moral theory an ontologically objective one? Or is it ontologically subjective like conscious states?

Harris says that the scientific theory of morals should take into account states of consciousness and should promote those indicate the "well-being" of a person. Apparently advances in neuroscience and a better scientific understanding of consciousness will help us understand "well-being" neurobiologically i.e. scientifically i.e. objectively.

Therefore, we can have not just a descriptive scientific theory of morality but a prescriptive theory too. It will work like this. It will allow a person to make decisions that maximize his or her well-being. And since future developments in neuroscience will allow us to define "well-being" objectively, in terms of a person's conscious states, our prescriptive theory of morals will be objective also.

Well, not so fast.

If well-being is a conscious state, is it ontologically subjective or objective? If I know my Searle correctly, Searle thinks that ALL states of consciousness are ontologically subjective. So an algorithm that helps me make moral decisions depends on well-being, and well-being is ontologically subjective - how is a prescriptive theory of morals going to be ontologically objective?

Harris will probably say that this is wrong, a theory of consciousness will result in a definition of well-being that is ontologically objective. He gives this analogy in support:

As I said in my talk, the concept of "well-being," like the concept of "health," is truly open for revision and discovery.

So "well-being" is like health. I can prove someone is ill, even if he continues to deny it, by shoving a thermometer into his arm-pit and pointing out to him that his body temperature is higher than normal. A scientific theory of consciousness will allow us to produce thermometer-like instruments that can measure a person's well-being objectively, and thereby open the way to an ontologically objective prescriptive scientific theory of morals.

Whew. But this is all too abstract. Let's take specific cases and see how well this theory holds up.

Suppose I have a moral dilemma: should I take a job which lets me help people (which I want to do)? Or should I get a job which lets me do research on cognition (something that's not really going to help people, but which I would love to do)? Clearly I cannot do both. How will Harris' proposed theory help me? Presumably, it will calculate my well-being were I to choose any one of these alternatives and then tell me the one that maximizes my well-being.

But consider, dear reader, whatever I decide, I will miss something, yes? And that something will affect my state of well-being, no? If I decide to do research in cognition, what makes this a better moral choice? But there's more. The algorithm has to calculate my future well-being if it can help me make a choice. How does it do that? If I do choose a career as a researcher in cognition on the algorithm's recommendation and I hate it (because I don't get along with my colleagues), isn't the algorithm wrong?

But you will probably say that I am missing the point.

Harris doesn't want a theory that helps us make these day-to-day personal decisions.

He wants a theory that can yield results like these: (1) Not wearing a veil is objectively better than wearing a veil because it promotes a better state of well-being. (2) Liberal secular democracies are objectively better than theocracies because the "well-being" promoted by the former is greater than that promoted by the latter. (3) The "well-being" of religious people is objectively less than that of atheists or non-religious people. You get the drift.

I wish with all my heart that a theory that proves these things objectively will come into existence. But this reveals all the weaknesses in Harris' piece.

First of all, why should a prescriptive theory of morals apply only to these situations and not to my day-to-day personal decisions? After all if well-being can be defined in an ontologically objective way, then it should also apply to ALL decisions that affect my well-being, no?

But second, how is this prescriptive theory going to account for a woman who chooses to wear a burqua outside? And insists that she feels better with it. Harris would presumably drag her, kicking and screaming, to his well-being center, wire up her brain and demonstrate triumphantly to her that she really isn't well, despite her assertions to the contrary.

Harris would be far better off trying to define his "well-being" concept in terms of concrete things. E.g. by using statistics that demonstrate the better health, mobility, longer life, etc. of women who choose not to wear a veil to those who do. But that's not "objective" enough for him (it isn't, but I would be fine with that, it is far more coherent). People like him are always looking for "deep" reasons to demonstrate conclusions that are dear to them. And because Harris is a neurobiologist, he thinks some future scientific explanation of consciousness (derived, of course, from neuroscience) will help him with that. Well, best of luck with that!

[By the way, I see many parallels between this and the Marxist notion of "false consciousness."]

Calling all scientists and mathematicians

[This post doesn't really fall into the topics this blog is supposed to be about, but it's reasonably close. And besides, my other blog is too frivolous for it anyway.]

Jerry Coyne has a new essay in the New Republic on the split between science and religion, about "the never-ending attempt to reconcile science and religion, and why it is doomed to fail". Blah blah. I am of the firm opinion that the matter cannot be settled either way and this essay, like most others, manages to settle nothing. (See this rather interesting, but rather tendentious, response by Jim Manzi and this one by Alan Jacobs).

The reason for this post though is that I found some of the reasoning that Coyne uses near the end of his essay to be grossly misleading, although again, I can't make a cut-and-dried case for anything. Here is the objectionable graf:

The NOMA [Stephen Jay Gould's idea of science and religion being Non-Overlapping MagisteriA] solution falls apart for other reasons. Despite Gould's claims to the contrary, supernatural phenomena are not completely beyond the realm of science. All scientists can think of certain observations that would convince them of the existence of God or supernatural forces. In a letter to the American biologist Asa Gray, Darwin noted:

Your question what would convince me of Design is a poser. If I saw an angel come down to teach us good, and I was convinced from others seeing him that I was not mad, I should believe in design. If I could be convinced thoroughly that life and mind was in an unknown way a function of other imponderable force, I should be convinced. If man was made of brass or iron and no way connected with any other organism which had ever lived, I should perhaps be convinced. But this is childish writing.

Similarly, if a nine-hundred-foot-tall Jesus appeared to the residents of New York City, as he supposedly did to the evangelist Oral Roberts in Oklahoma, and this apparition were convincingly documented, most scientists would fall on their knees with hosannas.

Scientists do indeed rely on materialistic explanations of nature, but it is important to understand that this is not an a priori philosophical commitment. It is, rather, the best research strategy that has evolved from our long-standing experience with nature. There was a time when God was a part of science. Newton thought that his research on physics helped clarify God's celestial plan. So did Linnaeus, the Swedish botanist who devised our current scheme for organizing species. But over centuries of research we have learned that the idea "God did it" has never advanced our understanding of nature an iota, and that is why we abandoned it. In the early 1800s, the French mathematician Laplace presented Napoleon with a copy of his great five-volume work on the solar system, the Mechanique Celeste. Aware that the books contained no mention of God, Napoleon taunted him, "Monsieur Laplace, they tell me you have written this large book on the system of the universe, and have never even mentioned its Creator." Laplace answered, famously and brusquely: "Je n'avais pas besoin de cette hypothese-la," "I have had no need of that hypothesis." And scientists have not needed it since.

In a common error, Giberson confuses the strategic materialism of science with an absolute commitment to a philosophy of materialism. He claims that "if the face of Jesus appeared on Mount Rushmore with God's name signed underneath, geologists would still have to explain this curious phenomenon as an improbable byproduct of erosion and tectonics." Nonsense. There are so many phenomena that would raise the specter of God or other supernatural forces: faith healers could restore lost vision, the cancers of only good people could go into remission, the dead could return to life, we could find meaningful DNA sequences that could have been placed in our genome only by an intelligent agent, angels could appear in the sky. The fact that no such things have ever been scientifically documented gives us added confidence that we are right to stick with natural explanations for nature. And it explains why so many scientists, who have learned to disregard God as an explanation, have also discarded him as a possibility.

There is an interesting sleight-of-hand at work here. "If a nine-hundred-foot-tall Jesus appeared to the residents of New York City", Coyne says and if this was "convincingly documented", most scientists would start believing in God. You think so? I don't. There are a number of reasons why I think so but they call center on the meaning of the term "convincing documentation". How does one decide whether the documentation is "convincing"? Is there a definition of the term that most scientists would agree on? Because you see, if the documentation is not convincing enough then I can reject the nine-hundred feet tall statue of Jesus as the work of a scam artist while still asserting that science is not a priori indisposed to the idea of God.

Coyne further goes on to say that science is not philosophically committed to materialism; that rather, this is a pragmatic commitment, that scientists use it simply because it works. Again, I am unconvinced. I agree with Giberson's claim that "if the face of Jesus appeared on Mount Rushmore with God's name signed underneath, geologists would still have to explain this curious phenomenon as an improbable byproduct of erosion and tectonics." Coyne says this is nonsense, that were this to happen, he and his fellow scientists would convert to Christianity and take the scriptures literally. He, in fact, goes on to list other phenomena that will make him believe in God: "faith healers could restore lost vision, the cancers of only good people could go into remission, the dead could return to life, we could find meaningful DNA sequences that could have been placed in our genome only by an intelligent agent, angels could appear in the sky".

Nice try. But I'm not buying. My contention is this: should any of these things happen, not one scientist will take them as evidence of the existence of a Christian God. Rather, several other things will crop up: the validity of the documentation will come up, fraud will be suspected -- and at the end of it all, most scientists will believe that there is some unknown causal explanation at work here, something that will surface once more work is done -- and get to work on it pronto. (What do you think?)

Why does Coyne bring this up? I suspect this is a rhetorical gambit intended to play upon the image of the man of science in our culture today. This image, which most of us have, says that the scientist is a man who changes his mind by looking at the facts, that he never lets his facts be dictated by theory, that instead he changes his theories once the facts change. As opposed to this, the religious believer is one who doesn't change his mind even when when the facts say otherwise. So Coyne is saying: "Look, we scientists are ready to change our minds if such and such happens, whereas religious believers aren't even prepared to say such a thing!"

I am not saying that there isn't some truth to this popular image of religion and science. And I am pretty clear about which side I am on. But this notion in the popular imagination that there is something called a "fact" which scientists have easy access to, and which they use to change their theories has got to be contested -- at least a little bit. One of the reasons why science is so successful at what it does is precisely because scientists do not change their minds easily, that they stick with a problem, despite many setbacks they encounter at solving it. Thomas Kuhn's point in The Structure of Scientific Revolutions (a book I will talk about in length perhaps in another blog post in the future) is that the development of science proceeds in two alternate steps: a conceptual revolution that is followed by a period of what Kuhn calls "normal science" which is again followed by a conceptual revolution. In "normal science" scientists settle down with problems, which they model as puzzles. In doing so, they build their concepts further. While doing "normal science", scientists will massage their concepts to fit the data but they refrain from changing their concepts drastically. In other words, they do not lose their faith in their concepts, do not abandon them until a "crisis" (Kuhn's term) is reached. Then, and only then, do the concepts get radically revised.

I am oversimplifying what Kuhn says. But my broader point is that scientists have to have some kind of "faith" in their concepts in order to do normal science -- no science would get done if concepts were radically revised at the drop of a hat! The terms "normal science" or "puzzle solving" aren't meant to be pejorative either. They may sound unexciting -- who, after all, would want to do "normal" science? But the point is that these puzzles themselves are extraordinarily challenging even for the best and the brightest -- and cracking them gives a scientist fame and recognition among his colleagues. The community of scientists, to quote a metahpor used by (I think) Michael Polanyi, is like the blind man with a cane. He uses his cane to see what comes ahead, he gets better and better at using it with practice but he also has faith that the ground will not drop away under his feet suddenly. Scientists grope their way to knowledge. My point here is that science, like liberalism, has a set of implicit metaphysical commitments. These are not unchanging, they have evolved over the last five hundred years but nevertheless they exist.

Here's a thought experiment to see what I mean. Suppose there is an omnipotent God. Suppose that there is a woman in the last stages of a deadly cancer. Finally suppose that there is a faith healer. The faith healer appeals to God to save the woman. God decides that he will grant the healer's wish and the woman's cancer starts going into remission. Will the scientist accept the healer's explanation that God did this? Well, no. To a scientist a result is only a result if it is replicable as widely as possible. So the said scientist takes the healer to another woman who has the same condition as the healed woman, more or less. Now however God decides not to honor the faith healer's wish; there is no remission. Ergo, the scientist's point, that the faith healer is a scam artist, and the woman's remission was due to some unexplained causes which further research will bring to light. Well, you say, what will it take for the scientist to accept the healer's point, that it was indeed God who healed the woman? Here's my guess. He would take the healer to N number of similarly ill women and ask him to heal them. Even if all of them did get better (God allowing), the scientist is still free to think that the reason for this is some yet to be explained metabolic similarity between these women. Indeed, what may change is that the scientist now believes the healer to be sincere yet self-deluded and not, as he believed earlier, a scam artist.

I am not really sure where I'm going with all this. And I am sure there are many loopholes in what I have said. But that's just my point: there is no water tight way of saying that science is incompatible with literal belief. And frankly, aside from the policy implications for a democracy, by itself, it is an uninteresting question by itself.