Saving the symmetry principle, II: why distinctions matter

The flurry of tweets that followed my last post made it clear that there are quite a few interpretations of the sentence “people believe things just because they are true.” One question that came up was whether or not the distinction between truth and evidence is any use in understanding that sentence. I think it is. But even if it is not, I want to make the broader point that esoteric-seeming distinctions can make a big difference to the success of our interactions with the general public.

Here's an illustration. If a tree falls in a wood, and no-one is around to hear it, does it make a sound? Well, if by “making a sound” you mean “producing sound waves,” then the answer is clearly “yes.” On the other hand, if you mean “causing a human to experience a sound” then the answer is clearly “no.”

The distinction between producing sound waves and causing aural percepts is not one that most people care about. But if our aim is to give a sensible answer to the question posed, we don't have a choice but to make that distinction. If we don't make the distinction, our efforts to answer the question are likely to be wasted. And if we do, we do not need to do much else in order to reach agreement on an answer.

Now imagine we are answering the tree-felling question in a public forum. If we answer “yes,” without making the distinction I mentioned, then we should not be surprised if we are met with howls of protest from those who have tacitly taken “making a sound” to mean “causing a human to experience a sound.”

Of course it would be better if our readers made the distinction themselves, exercised charity and common sense, and assumed that we meant “producing sound waves.” But if we don't make the distinction, when it makes such a big difference to the correctness of our answer, then we can hardly complain if our audience does not do so either.

Conversly, if we are reading a popular text on tree-felling, and the author asserts that trees don't make sounds when they fall in empty forests, then we should not imagine that their claim is obviously, lamentably wrong. To do so would be to ignore the fact that they are half right. And to do that would be to repeat the author's real error, which was not to answer “no” rather than “yes” but to take the question as one rather than two.

Clearly there are many distinctions that are irrelevant to any given question. To answer our question about felled trees, it would not be much use to distinguish between tranverse and longitudinal waves. There are are also an infinite number of weird interpretations of a question, and no matter how careful we are to delimit our answers there is bound to be someone who takes it the wrong way.

(Example: many of the commentators on Vanessa Heggie's recent post seemed to think that she was advocating some sort of radical skepticism about science, which was pretty clearly not the point of the post.)

Philosophers are the specialists in conceptual distinctions, but we historians have a sense of why distinctions matter in general. Whereas philosophers tease apart the meanings of terms, historians are exquisitely sensitive to the peculiarities of different times, places, people, and episodes. The question “Is there a conflict between science and religion?” is meaningless to the historian in the same way that “Is the world one or many?” is meaningless to the philosopher. The answer to both is, “it depends.”

We should also bear in mind that academic study can cloud distinctions that are perfectly clear to non-experts. This does not always reflect well on the experts. Consider the distinction between statements about the world and the world itself. If ordinary people did not make this distinction they would have great difficulty getting through their lives without going mad or getting into terrible accidents.

Such people would automatically believe everything they read or heard, since they would not be able to grasp the idea of a false statement. They would live in a state of perpetual puzzlement as they witnessed objects and events that appeared to have no statements attached to them. In their confusion they might even mistake events for statements, wandering into the path of oncoming traffic in the belief that this wordly action is as harmless as the statement “there is oncoming traffic.”

Yet it is only a bit of an exaggeration to say that entire academic careers have been built around the denial of the distinction between the world and the things we say about it. Much of what is called the 'Science Wars' could have been avoided if both sides had been more careful to distinguish between the two things.

More generally, it has long been fashionable in the humanities to frame new ideas in terms of the erasure of one or other distinction that many people take for granted. There is no shortage of authors who claim to challenge the distinctions between subject and object, fact and fiction, fact and value, fact and theory, theory and practice, art and science, etc. It is a long time since I read a book in science studies that promised to mark out a boundary rather than transgressing one, or to heed a dichotomy rather than interrogating one.

I'm not saying that all this distinction-denying is a bad thing. My point is that academic study blinds us to the ubiquity of the distinctions we deny just as surely as it blinds us to the abstruseness of the distinctions that are commonplace in our chosen field.

What about the distinction between truth and evidence, which I fussed over in my previous post? Is it esoteric like the one between “producing sound waves” and “causing a human to experience a sound”? Or is it more like the distinction between “statements about the world” and “the world itself,” ie. a commonplace that only sophisticated people fail to grasp?

I don't know. But the main message of this post is that it doesn't matter. If the distinction helps us to answer the question at hand then it is worth caring about, no matter how ordinary or esoteric it might be.

The question at hand—to get back to the topic of this series—is whether the symmetry principle is right in stating that people do not believe things just because they are true. The aim of my next post is to give a list of distinctions that make a difference to how we answer this question. Expand post.

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Saving the symmetry principle, I: two fallacies

Vanessa Heggie has posted a clear, visible summary of what she rightly calls a “core principle” for historians of science, namely the “symmetry principle.” So this is a great opportunity for me to explain why I disagree with much that my fellow historians of science have written on this topic. Behind the symmetry principle there is an insight that is true, important and worth keeping. But we need to save this insight from the ideas that are often associated with it, many of which I think we should reject.

The basic insight is that there is a certain inference, which I will call The Fallacy, that is a tempting yet unreliable way of way of explaining the beliefs of past scientists. The point of this post, the first in a series, is to separate The Fallacy from another fallacy that is so unappealing that no-one had even thought of it before historians of science started finding it everywhere.


The Fallacy

Consider Galileo's theory that the uneven shading of the moon is due to the shadows cast by hills and mountains on the moon's surface. Most of us prefer this theory to one of its seventeenth-century rivals, according to which the moon is a perfectly smooth sphere whose visible blotches are due to the uneven density of the crystalline matter of which it is made.

The fallacy is to say that since the theory is true, Galileo must have believed it because of the evidence in its favour, while those who rejected it must have done so out of superstition, prejudice or self-interest. In general:

Theory X is true, therefore everyone who held it did so for good reasons, while everyone who denied it did so for bad reasons.

This is what I will call The Fallacy. As I have stated it, this fallacy applies to two people with conflicting beliefs, but this limitation is one of convenience rather than necessity. The same kind of fallacy could be applied to two beliefs that have opposite truth-values but that do not contradict each-other. Or it could be applied to two beliefs held by the same individual. Or it could be of these cases in one.

For an example of the latter, consider Galileo's theory that comets are exhalations that mount in a straight line from the surface of the earth. The fallacy would be to infer from the truth of Galileo's moon theory that he held it from a combination of accurate observation and sound inference, and from the falsity of his comet theory that he held it out of dogmatism, amour propre, etc.


The Other Fallacy

It may look like I have simply repeated Vanessa's account with a different example (she uses Leibniz v Newton rather than Galileo). But there's a crucial difference. The teaser at the top of Vanessa's post says that “No one believes something simply because it is true”, and the fifth paragraph urges historians to “forego the assumption that [Newton] believed in his law of gravity because it was true.” This suggests that the fallacy that Vanessa has in mind is something like this:

Theory X is true, therefore everyone who held it did so because it was true, while everyone who denied it did so for bad reasons.

Call this the The Other Fallacy. It is the same as The Fallacy except that it replaces “good reasons” with “truth” as an explanation of the true beliefs of past scientists.

Although The Other Fallacy is indeed a fallacy, I think it is a very rare one, even among the most Whiggish of old-fashioned historians. Imagine asking George Sarton (to pick one such historian) why Copernicus believed that the earth goes round the sun. Would Sarton have said “because the earth does indeed go around the sun”, or perhaps “because Copernicus thought 'the earth goes around the sun' was a true statement”?

I doubt it. Instead he would have said something like: “because Copernicus looked at a whole lot of data, did a bunch of calculations, and found that a number of key phenomena—such as the retrograde motions of the planets and the fact that he never observed Mercury and Venus on the opposite side of the earth to the sun—could be explained in very neat manner by supposing that the earth is just another planet.”

To put one of the first two replies in Sarton's mouth is to commit what I have called the constructivist straw man. Another way to commit the same error is to say that Sarton and his ilk denied that “human agency” or “human activity” played any role in the beliefs of scientists.

Both forms of the straw man can be found in this transcript, which Vanessa links to in her post. First comes the suggestion that, some time in the seventies or eighties, historians started to see scientific knowledge has “a human product, something that had to be made and maintained.” In other words, earlier historians had thought that “true knowledge was immaculate, untouched by human hands.” (This is true only on the perverse assumption that calculating, experimenting, and reasoning—the sorts of things that interested Sarton et. al.—do not count as human activities).

Next in the transcript comes the misattribution that lies behind The Other Fallacy. How did these earlier historians explain the beliefs of scientists, if not as the result of human action? Answer: by appeal to the truth of those beliefs. For example, they would “say that Isaac Newton thought that there was an inverse square law of gravity acting instantly at a distance through empty space between the centers of distant bodies because there is [such a law].”

(Disclaimer: the historian featured in this transcript is my thesis advisor. Clarification: yes, I am disagreeing with my thesis advisor on this point, although I agree with him on much else.)

The problem with The Other Fallacy is that it sets the bar too low. A campaign against it is like an anti-smoking campaign that urges smokers to stop committing murders. Since most smokers are not murderers, the campaign is unlikely to have any effect except perhaps to convince non-smokers that many smokers are, in fact, murderers.

Likewise, urging people to avoid The Other Fallacy is unlikely to solve the real problem, which is The Fallacy. Those who commit the latter are likely to continue doing so, happy in the knowledge that they have not committed The Other Fallacy. And those who avoid The Other Fallacy may end up convincing themselves that everyone else is more wrong-headed than they really are.


Truth and evidence are not the same thing, and it matters

Perhaps historians attack The Other Fallacy, rather than The Fallacy, because the two are hard to tell apart. After all, as noted above, the only difference between them is that between explaining a person's belief by its truth, and explaining that belief by the arguments or evidence that the person found in its favour. And aren't these pretty much the same thing?

No! In the context of a debate, whether in the present or in the past, they are completely different beasts.

This is easy to see from the three quotes I put in the mouth of George Sarton. Imagine if we tried putting those quotes into the mouth of Copernicus rather than Sarton. Does the De Revolutionibus contain statements like: “'the earth moves around the sun' is a true statement, therefore the earth moves around the sun”? Or statements like: “the earth moves around the sun, therefore you should believe that the earth moves round the sun”?

Probably not. Or if it does, they were not the sorts of statement that convinced people that the earth went around the sun. And nor are they the sorts of statement that are used today to convince people that vaccinations work, or that climate change is real, or that God does or does not exist. And this is not something that “modern historians” discovered some time in the seventies and eighties. No sane person has ever denied it.

This should be uncontroversial. Granted, there are controversial issues nearby. There are the questions of the extent to which standards of evidence have varied over time and place, whether there is some super-standard that allows us to assess this alleged multiplicity of standards, whether evidence can reliably inform us about unobservable entities like quarks and quasars, and whether evidence can be decisive in resolving scientific disputes. But we do not need to agree on any of these issues in order to agree that giving evidence for a proposition is different from asserting that the proposition is true.

This large, uncontroversial difference does not stop historians of science running the two together as if they were the same thing, usually when passing judgement on dead historians of science. I've already given one example from a prominent historian. Here's another, from Stephen Shapin's 2010 book Never Pure:

Once upon a time, so the story goes, students of science too believed that truth was its own recommendation, or, if not that, something very like it. If one wanted to know, and one rarely did, why it was that true propositions were credible, one was referred back to their truth, to the evidence for them, or to those methodical procedures the unambiguous following of which testified to the truth of the product.

In this passage Shapin at least recognises that the truth of a claim and the evidence for it are different things. But only just: he also says that they are “very like” each-other. He implies, absurdly, that students of science used to be uninterested in how scientists justified their beliefs. And on the preceeding page he attributes to an unnamed group of “modernist methodologists”—presumably people like Hans Reichenbach, Rudolph Carnap, and Karl Popper—the view that “truth shines by its own light.”

The conflation of truth and justification does an injustice not only to old-fashioned historians like Sarton but also to present-day internalists. The latter may be defined as historians of science whose main interest is the mixture of luck, skill and insight by which past scientists—as individuals or as groups, over months or over centuries—developed arguments for their claims the natural world.

Internalists can be as symmetric as anyone, giving as much attention to the errors of “winners” as they do the insights of the “losers.” They do not give complete accounts of their subject (show me a historian who does!). But they do far more than simply put tautologies in the mouths of past scientists.

To sum up, by conflating truth and evidence we make the latter look as unimportant as the former in the resolution of debates, whether in the present or the past. This is an error as bad as The Fallacy. It is silly to appeal to the presumed truth of a claim in order to persuade people that the claim is true. By contrast, it is silly not to appeal to the presumed evidence for the claim in order to persuade people that the claim is true.

Having identified what I think is the good idea behind the symmetry principle, in my next post I hope to explain why it is a good idea. This can be done, but it is harder to do than my colleagues usually make out.



Postscript 1. If the error that I am attributing to my fellow historians is such a bad one, why had no-one spotted it until now? Actually, at least one person had. Ian Hacking wrote the following in a footnote to his 1999 book The Social Construction of What?:

Evidence, or reasonableness, is quite another matter from truth. [The sociologists of science Barry Barnes and David Bloor] are often taken to hold a symmetry thesis about evidence: you cannot invoke the evidence available to a community for a belief p, in order to explain why people in the community believed p... I find this claim (about evidence, not truth) unsatisfactory (232).

Why did Hacking put this point in a footnote rather than in the main text? Because he only mentioned the symmetry principle on his way to talking about something else, and that thing (the distinction between “nominalism” and “inherent-structurism”) was relevant to truth and not to evidence.

I'm still trying to work out why other commentators on the symmetry principle have not made the point that Hacking made in his footnote, and that I made in the above post. I'ld be delighted to know of any examples of people who have made the point in print.


Postscript 2. Maybe I'm being too harsh. Maybe Shapin et. al. want to draw the following contrast. One can say that a scientist believed P because they were convinced, on the basis of the evidence, that it was true. Or one can say that the person believed P because they were convinced, independently of their views of the truth-value of P, that it was in their interests to believe it.

On this reading, “No-one believes things just because they are true” is shorthand for “No-one believes things just because they are convinced, on the basis of the available evidence, that they are true.”

But if this is what is meant, why not just say “No-one believes things just because they have evidence for them”? This would make it clear that evidence is involved. Or what about saying “No-one believes things just because they believe them to be true”? This would at least make it clear that it is not the truth of a person's belief that is under consideration but the person's conviction that it is true.

Both of these clearer expressions would avoid the rhetorical sleight-of-hand that is involved in saying “No-one believes things just because they are true” when what you mean is “No-one believes things just because there is evidence for them.” The former claim is obviously true. The latter claim may be true, but not obviously so. The ambiguity has the effect of making the intended claim (if the intended claim is indeed the latter one) more obvious than it really is.

But all this may be moot, since I doubt that my charitable reading is correct. I suspect that Shapin et. al. really are accusing past historians and philosophers of thinking that the truth of a scientist's belief (and not just the scientist's conviction of its truth) can be a good explanation of that belief.

One reason for my doubt is that, in the passage quoted above, Shapin includes “truth” and “evidence” as separate items in his list of candidate explanations for the beliefs of past scientists. This suggests that he is not implicitly including “evidence” under the rubric of “truth.” If he were, then it would be redundant to include evidence as a separate item.

Another reason to be skeptical is that, as I understand them, even sociologists of science have trouble making sense of the idea that people can believe things without first being convinced of their truth. That is, sociologists would probably not say “Newton believed his inverse square law because, although he withheld judgement about the truth-value of the law, he thought that this belief would protect his reputation as a national hero.” Rather, their explanation would be something like: “Newton believed his inverse square law because he thought the law was true, and an important source of this conviction was (not the evidence but) his desire to protect his reputation.”

At least, that is what I imagine they would say. And if that is right, even sociologists think that people “believe things just because they are convinced of the truth of those things.” So that cannot be the allegedly false view that Shapin et. al. are attributing to past historians and philosophers of science. The view they are attributing must be the one I assumed in the above post, viz. that people believe things just because those things are, in fact, true. Expand post.

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13 things Gopnik got right about Galileo

Since you are reading this, you have probably read Adam Gopnik's recent essay-review about Galileo Galilei in The New Yorker. You might also have seen some reactions from unimpressed historians, one of whom calls the article “extremely pernicious.” I think that some of Gopnik's errors have been exaggerated, and that most of his felicities have gone unnoticed. The moral is that us historians should be as alert to what popular writers get right as we are to what they get wrong. After all, we can hardly criticise Gopnik for imbalance in his treatment of Galileo if we are imbalanced in our treatment of Gopnik.

To avoid over-balancing in Gopnik's favour, I've included some new “cons” next to some of the thirteen “pros” below. Most of the items on this selective list are included because they are pleasant surprises, ie. claims about Galileo that show a healthy level of historical acumen for someone who does not do history for a living. For example, if Gopnik had not made point 12 below, many would have privately groaned at his naive belief that science is insulated from its cultural context.

I'm not suggesting that historians should give a point-by-point assessment of every popular article they comment on; that would paralyse commentary. I've got nothing against the practice of picking out one error from a feature article and tearing it to shreds, as thonyc has done with the Gopnik's comparison between Dee and Galileo. But I do think that we should read popular articles as if we were about to write an analysis like the one I've tried to present in this post. If we look for pleasant surprises, we might find more of them than we expected.

My list covers three topics, in this order: Galileo and the Church, Galileo's science, and Galileo's context. My main source on Galileo is one of the subjects of Gopnik's review, an excellent 2010 biography by John Heilbron—the same John Heilbron who starred as Thomas Kuhn's student in my previous post.


Galileo and the Church

One. Gopnik writes that Galileo's conflict with the Catholic Church was “traceable to his hubris.” This should please those who say, with Thomas Mayer, that “the fault [for the condemnation of Galileo] lies with Galileo, not the pope or the Inquisition” (quoted in this news article.)

(Mayer is the author of two works that Gopnik covers in his review; his take on Gopnik's article can be found in the comments of this post. I hope to read Mayer's books in full at some point, but for now I am relying on the snippets from their introductions that are available on Google Books).

In fact, the theme of Galileo's insolence in was strong enough in Gopnik's article to antagonise a blogger at the Cato Institute, who read Gopnik as saying that “Galileo could have avoided a lot of trouble if he'd been just a little less stubborn and impolitic.”

Two. “The Catholic Church in Italy then was very much like the Communist Party in China now: an institution in which few of the rulers took their own ideology seriously but still held a monopoly on moral and legal authority. … Like the Party in China now, the Church then was pluralistic in practice about everything except an affront to its core powers. … You could calculate, consider, and even hypothesize with Copernicus. You just couldn’t believe in him.”

Gopnik is right that the Church could tolerate a large amount of Copernican science, especially when it was useful for things like making calendars. This is a key point that is often missed by those who take a black-and-white view of Galileo's conflict with the Church.

On the other hand, I'm not sure where Gopnik got the idea that the rulers of the Catholic Church in Galileo's time did not take religion seriously. Even Galileo was a man of faith, at least according to Heilbron, who thinks that he “believed as surely as Bellarmine [the Pope's chief theologian until his death in 1621] and the majority of Catholic exegetes of their time that every statement in scripture is in some sense true.”

But Gopnik is right that the Church was especially sensitive to doctrinal violations that posed a threat to its power:

“In Rome they pardon atheists, sodomites, libertines, and other sorts of rascals, but they never pardon those who bad mouth the Pope or his court, or who seem to question papal power” (needless to say, I got this quote from Heilbron's biography, who attributes it to Gabriel Naudé, the librarian of Urban VIII's nephew).

Three. “Galileo even seems to have had six interviews with the sympathetic new Pope, Urban VIII—a member of the sophisticated Barberini family—in which he was more or less promised freedom of expression in exchange for keeping quiet about his Copernicanism.”

This is not the sort of concession you would expect from someone who wants to show that there was no room for compromise between Galileo and the Church.

Gopnik could have added that Urban VIII was not only willing to publish Galileo's Dialogue on the Two Chief World Systems (the book that triggered Galileo's 1633 trial) but that he considered it useful for the church. By showing that he knew all of the arguments in favour of the Copernican hypothesis, Galileo would show that he—along with all good Roman Catholics—had rejected that hypothesis out of piety and epistemic humility and not out of ignorance.

I bring this up not to suggest that Gopnik should have mentioned it in his article, but because it must be one of the craftiest rhetorical manoeuvres in the history of Church-science relations.

Four. “Though Galileo, vain as ever, thought he could finesse the point, Copernicanism was at the heart of what he wanted to express.”

This sentence is a pretty good summary of Galileo's motivations for publishing his Dialogue. It captures the depth of Galileo's Copernican commitment, and the foolishness of his belief that he could dodge censure with verbal trickery.

Five. “Galileo’s trial was a bureaucratic muddle, with crossing lines of responsibility, and it left fruitfully unsettled the question of whether Copernican ideas had been declared heretical or if Galileo had simply been condemned as an individual for continuing to promote them after he had promised not to.”

“Bureaucratic muddle” echoes Mayer's point, reported in this 2010 article, that the irregularities of Galileo's trial were due to ineptitude rather than malice on the part of Church bureaucrats. The rest of the quoted sentence shows that Gopnik grasps Mayer's point, reported in the same article, that Galileo's punishment in 1633 was at least partly due to his violation of a precept issued against him in 1616.

On the minus side, Gopnik omits another of Mayer's points, which is that Galileo was as clumsy as his judges, ie. he made things worse not just through “vanity” or “hubris” but also through sheer legal incompetence.

Six. Other scientists have followed Galileo in “ducking and avoiding the consequences of what they discovered”; in general, “science demands heroic minds, but not heroic morals.”

These claims, from the final paragraph of Gopnik's article, arguably make Galileo into even less a hero than he really was. Between his Sunspot Letters of 1613 and his trial in 1633, and especially before the precept issued against him in 1616, Galileo often did the opposite of “ducking and avoiding” the consequences of his Copernican views.


Galileo's science

Seven. Gopnik notes that Galileo's astronomical observations were due to his powers of his interpretation rather than his knowledge of the telescope, and that he did not invent that instrument: “since there were Dutch gadgets in many hands [by the time Galileo made the key observations], and many eyes, he understood what he was seeing as no man of his time had before.”

Eight. Despite being a “founder of modern science,” Galileo wrote things that we consider false today, notably that the orbits of the planets around the sun are circular and that the tides are due to the sloshing caused by the acceleration and deceleration of different parts of the earth. As Gopnik puts it, he “had his crotchets.” Moreover, Gopnik suggests that he went wrong about the tides precisely because of the skepticism that makes him seem modern (shades of Paul Feyerabend?).

A minor quibble is that Gopnik does not mention the best illustration of this theme, Galileo's 1623 book on comets, the Assayer. Heilbron shows that this work, which contains some of Galileo's most famous remarks about scientific method, was riddled with scientific errors and written out of groundless spite.

A bigger complaint is that Gopnik does not mention that Galileo overstated the case for Copernicanism. Many of his arguments showed only that the earth's motion was consistent with sense experience, he completely ignored a compromise model put forward by the great astronomer Tycho Brahe, and his favourite argument for the motion of the earth was based on his dodgy theory of the tides. Many of Galileo's contemporaries, including some of his close friends, were aware of these problems. Heilbron puts it like this: “although [reason and experience] established essential and growing support for Copernican theory [by 1616], it gave no unimpeachable proof.”

Nine. The Dialogue did not express a straightforward view about scientific method: “Though Galileo/Salviati wants to convince Simplicio and Sagredo of the importance of looking for yourself, he also wants to convince them of the importance of not looking for yourself.”

On the minus side, Gopnik may be too generous when he implies that this two-faced attitude is “philosophically sophisticated.” Perhaps Galileo championed observation when it suited his case, and favoured a priori reflection when sense experience worked against him.

Ten. “The temperament [of Galileo] is not all-seeing and curious; it is, instead, irritable and impatient with the usual stories.”

This is not a bad paraphrase of Heilbron's point that “perhaps the best single-word descriptor of Galileo is 'critic.'” On the other hand, the reference to "usual stories" is misleading, since Galileo was often a conservative critic. This from pages 1 and 2 of Heilbron's biography:

Galileo was a humanist of the old school. He much preferred Ariosto, the darling poet of the sixteenth century, to Tasso, who would be a favorite of the seventeenth... He stayed with the geometry of the Greeks rather than employ the algebras of his contemporaries... He was not an innovator by temperament. And, we are told, he liked to wear clothes that were fifty years out of date.

Another limit on Galileo's critical spirit was that he had trouble applying it to himself. Few people were convinced by Galileo's theory of the tides when he showed it off in Rome in 1615-16. Galileo must have been aware of the weaknesses of the theory, but once he got hold of it he could not let go.

Gopnik's comparison between Galileo's temperament and that of his near-contemporary, John Dee, has been ripped apart by thonyc. I'm not going to try to put the pieces back together. But it does seem that the fault, if there is any, lies less with Gopnik that it does with his source. Gopnik could not have guessed that the biography he reviewed left out most of Dee's contributions to modern science, as thonyc seems to say it did.


Galileo's context

Eleven. The Dialogue was as much a literary achievement as a technical one. Indeed, “it uses every device of Renaissance humanism: irony, drama, comedy, sarcasm, pointed conflict, and a special kind of fantastic poetry.”

Twelve. Galileo's “primary education” was in such things as music, drawing, poetry and rhetoric; and this cultural context had an effect on his natural philosophy. It gave him a “competitive, empirical drive” and “intellectual practices of doubting authority and trying out experiments.”

A tick for paying attention to context, but possibly a cross for doing so selectively. Gopnik does not mention Heilbron's thesis that Galileo's early literary tastes foretold his black-and-white approach to debates, his heroic self-image, and (remarkably) the absence of the crucial notion of “force” in his mechanics. A determined critic might say that Gopnik has fastened on the cultural elements that make Galileo an ideal modern scientist, and ignored the rest.

Thirteen. Galileo framed his discoveries so as to appeal to patrons: “A Tuscan opportunist to the bone, Galileo rushed off letters to the Medici duke in Florence, hinting that, in exchange for a job, he would name the new stars [ie. the moons of Jupiter] after the Medici.” Similarly, the telescope was not just a technical device for Galileo, but an “emblem and icon,” part of his “image.”

These are key themes in Mario Biagioli's 1994 book Galileo, Courtier. True, Gopnik probably got this information second-hand, from Heilbron's biography. But it does not follow, as Darin Hayton has suggested, that he “ignores considerable recent work on Galileo.”


*******


Gopnik's main errors, in approximate order of seriousness, are to ignore Galileo's overstatement of the Copernican case, to ignore the conservatism and dogmatism that went with his critical spirit, to underestimate the sincerity of his religious faith, to neglect Heilbron's novel and striking thesis about the relevance of Galileo's early literary tastes to his later career, and to omit Mayer's point that Galileo made elementary legal mistakes during his trial.

These errors should be seen alongside the many pleasant surprises listed above, of which the most gratifying are, in my opinion, the recognition that Galileo was vain and stubborn, that the Church supported much Copernican science in Galileo's time, that the Pope himself agreed to the publication of an anti-realist version of the Dialogue, and that Galileo's critical spirit was partly responsible for his rejection of Kepler's ellipses and his acceptance of a mechanical tidal theory, two moves that we now regard as major blunders.

In my view, and keeping in mind that this is a popular article by a non-specialist author, the pros outweigh the cons by a clear margin. If an unprejudiced non-historian reads Gopnik's article with care, there is a good chance that he or she will come away with a more nuanced and accurate view of the Galileo affair than they started with.

In my next post I intend to look at some more general issues that the “Gopnik affair” raises about history-of-science communication. Expand post.

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