Looking twice at the history of science

Thursday, May 29, 2014

Saving the symmetry principle IV: from symmetry to asymmetry

The symmetry principle has been a central tenet of the history of science since at least the 1970s, and in my view it is a sound and valuable principle. However it is often confused with principles that are neither sound nor valuable, some of which are positively harmful for the study of past science. For example, the symmetry principle is sometimes expressed as the view that “truth” cannot explain the beliefs of past scientists. My main aim in this series so far has been to show that this view is hopelessly vague, and that on many readings it is false. In this post I will say the same about another aspect of the symmetry principle, namely the claim that historians should explain true and false beliefs “in the same way.” I’ll run through five readings of this claim, only the first of which deserves to be called the symmetry principle. Expand post.


  1. Welcome back, Michael - I think this is a very useful delineation of historiographical strategies. I have a couple of thoughts:

    1) I think your average relativist would reject, as a methodological tenet, the possibility of delineating "good" reasons, since goodness would be taken to be a contested category. Thus the methodological relativist would not omit good reasons, so much as focus in on those places where goodness was explicitly contested. This could occur at the level of the quality of instrument or technical argument, or the integrity of the experimenter, or the entire research program she or he represents. Although such relativism is intended to flesh out various hidden preconditions for agreement, you are right that it does tend to exclude reasons that are not contested, either because they occur at a deep level of argument that is excluded because criticism is leveled at a more fundamental/programmatic level; or because there is broad agreement about the validity of the reason.

    Otto Sibum's work on Joule's experimental technique is an excellent example of work that detects reasons that would not show up in a relativist account because they were not explicitly contested.

    2) I think it is important to recognize that the legitimacy of asymmetric approaches parading under the banner of symmetry (and the preponderance of "bad" reasons in such approaches) is often premised on the idea that they are intended to be read against a "received" or "scientists'" view, or an "official history," all supposedly dominated by "good" reasons (probably defined in a presentist frame). See my posts on "Kuhn's Demon" and Malcolm Ashmore's radically corrective account of the N-rays episode.

    1. Hi Will, thanks for replying with your usual alacrity.

      1) I hesitated a lot before deciding to use the terms "good" and "bad" rather than the more common "social" and "cognitive." This is not just a terminological matter, since there can be bad cognitive reasons and good social reasons for believing something. Examples of the former can found in the first paragraph on the Exclusion Principle in the post; an example of the latter might be to believe a theory in climate science because most people with PhDs in climate science endorse the theory.

      The reason I chose the good/bad distinction is because I believe it is the distinction that people have in mind when they commit The Fallacy. Why are tempted to believe that Galileo's moon theory was caused by observations and experiments rather than by self-interest? Is it because we consider self-interest to be a social matter rather than a cognitive matter? Or is it because we consider self-interest to be a bad reason for holding a belief, ie. a reason that is going to lead to lots of false beliefs in the long run? Speaking for myself, I think the latter is the deeper answer. Self-interest is indeed a social matter, but it is not because it is social that we are tempted to commit The Fallacy, but rather because it is a bad way to form beliefs.

      As you point out, the problem with the using the terms "good" and "bad" is that they wear their normativity on their sleeve. However I don't think this should prevent the relativist from endorsing the Symmetry Principle as I have stated it. The relativist could just read "good" as "good relative to the 21st century," or "good relative to the historian in question."

      You are right that the methodological relativist would not entirely exclude good reasons from their account. However the usual move is to identify reasons that are good (relative to us) on both sides of a past debate, and then use this observation to justify a social explanation of the outcome of the debate. So good reasons are present, but they "dominate" the bad reasons in the explanations that the methodological relativist gives.

      I should add that I have been using the phrases "good reasons" and "bad reasons" as short-hand for the phrases "good epistemic reasons" and "bad epistemic reasons." If you want to hold true beliefs, then self-interest is a bad reason to hold a belief. But if you want to make money or gain power, then self-interest may be a good reason to hold certain beliefs. My terms are not meant to imply that the pursuit of truth is morally superior to the pursuit of self-interest.

    2. 2) Agreed: one route to asymmetry is the desire to correct the opposite asymmetry and thereby restore symmetry overall. This is a good route to follow, I think, as long it is clear how much of the old account is being rejected in the revision. The problem is that often this is far from clear, as you discussed here:

      But wait: in the above post I implied that charitable reading, not clear writing, was key. Were we too hard on Schaffer's account of the reception of Newton's prism experiments? Should we be more charitable, and assume that he was trying to complement the received account of those experiments rather than replace it? More generally, when should the author specify the scope of their arguments and when can they reasonably leave this task to their readers?

      I don't have a complete answer to these question, but I think two factors are important: the writer's purpose and the reader's interests.

      If the main point of your book/article is to draw attention to factor X, then it would be natural to say something about the relative importance of factors X, Y and Z (if only to say that their relative importance is hard to guage).

      Suppose that highlighting factor X is not the main point of the work, but that the work happens to discuss factor X. Suppose also that the question of the relative importance of X, Y and Z is a controversial issue that is high on the discipline's agenda at the time of writing, such that most readers will be interested in what the author has to say on the topic. In such a case it would also be natural for the author to say something about it (if only to say that he considers the topic an over-hyped one about which he has nothing new to say).

      I'ld have to read Schaffer's paper again to work out whether he falls foul to one of these requirements. But it's more important to state these requirements (supposing that they are reasonable requirements) that to work out whether this or that author violates them in this or that paper.

    3. Thanks for your replies, Michael. Your response to my (2) reminds me again of my feeling that historiographical problems often cast as turning on deep epistemological problems often can be recast as meat-and-potatoes problems in the craft of history-writing: how do you engage with an existing literature, for example. While it is tempting to blame confusion concerning an author's intent on bad writing, I tend to think that maintaining plausible deniability plays an unfortunately large role in legitimizing radical-sounding claims and a historiography whose chief accomplishments are usually framed only in the vaguest terms. Which is too bad, because as we agree, the historiography has accomplished numerous useful things.

      We've been over these points before, I believe, but it's always nice to rehash how they call connect.

    4. A loose note: the feeling you describe in your second sentence is one that many historians are having about their subject matter, ie. we feel that "scientific debates often cast as turning on deep epistemological problems often can be recast as meat-and-potatoes problems in the craft of science." A cause for optimism, perhaps? After all, those who appreciate the point about past science should be able to appreciate your point about recent historiography.

      Spotting the typo in the last paragraph in my last post is an exercise that I will leave to the reader.

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  3. In keeping with the multipart nature of the series, this is the first of my four comments.

    Since it's been awhile, I just reread the whole series (comments included). It all started with an interview that Simon Schaffer gave CBC. In this comment, I just want to transcribe a bit of what he said.

    Knowledge is an institution, and it should be analyzed as such. .... That meant, for example, that it was extremely unpromising, to put it mildly, to suppose that social principles are only acting when folks get things wrong. So for example, it didn’t look remotely plausible to 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 an inverse square law acting instantly from the center of one body to another through empty space, and Leibniz disagreed because he was German.

    That's to explain the truth one way, that's to say to explain what we think is so one way, and to explain what we don't think is so a completely different way. As though there are these things called social forces which wreck our ability to see how things are. What we learned was that there are social institutions at work to produce what we know. And indeed to produce what anybody claims to know, at any particular period. ... It seemed to us, and it still seems to me, that people in social groups build their knowledge like they build other institutions, and you should analyze how they do that the way you analyze the the institutions people build. ... That meant therefore that it would be a great idea, a really really good idea, to look at controversies both in the present and in the past. ...To use a phrase from I think one of the most important sociologists of scientific knowledge, Harry Collins, you could see how the ship gets in the bottle.

    Note the seamless transition from a version of the symmetry principle to social constructivism. Also note Schaffer's example: he accuses an unnamed (or generic) historian of claiming that Newton believed his law of gravity because it was true.

    Finally, our frequent participant Jim Grozier has an interesting post up on Harry Collins: Harry Collins and Tacit Knowledge.

    Complete Schaffer interview: How To Think About Science, Part 1.

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  5. The issue of Relativism vs. Truth reared its head earlier in this series, and you proposed a way to avoid its seductive but dangerous entanglements: talk about the reasons people believed things: evidence vs. social and psychological factors.

    I paraphrase, and I wonder if some standard terminology holds sway in the field. Cognitive or epistemic reasons? Internal vs. external? In this post, at least, you adopt the dichotomy Good vs. Bad. Obviously confusion could run rampant, and careful distinctions should be drawn (and quartered), much like you did for "fact".

    To kick-start the dissection, let me ask a few questions.

    Does evidence (or good reasons) include everything regarded as legitimate by the historical figures? I have in mind, specifically, scriptural and theological arguments. Galileo and his opponents traded them, as did Newton and Leibniz, and I believe (but am not sure) that they midwifed D'Alembert's principle of least action.

    In contrast, we have such factors as currying favor, personal dislike, egotism, wishful thinking.

    This suggests a touchstone for the distinction: "evidence" is anything explicitly mentioned by the participants. The records of Galileo affair, for example, nowhere include a notation, "Hey, the Counter Reformation is in full swing, we don't have time for his crap, squelch him."

    I suspect this "touchstone" won't hold up under severe analysis, but watching it disintegrate could prove instructive.

    A post by Thony (Gopnik, Galileo and Ed Yong: Galileo not admitting to being wrong) adds another wrinkle. Thony uses the words "bamboozled" and "deceptive" about Galileo's tidal theory, raising the question: did Galileo even believe it himself? Perhaps he just needed proof of heliocentricity, and thought his opponents were easy marks. Should we count as "evidence" all arguments the protagonists made, even if we suspect they were arguing in bad faith?

    Thus, my preliminary classifications of reasons:

    1. Arguments made explicitly at the time, regarded as legitimate today (e.g., Newtonian predictions of celestial observations). Subcategories: good faith, bad faith.

    2. Arguments made explicitly at the time, no longer regarded as legitimate in the scientific community (e.g., scriptural evidence). Subcategories: good faith, bad faith.

    3. Social factors, not explicitly mentioned, that may have consciously or unconsciously influenced a protagonist (e.g., desire for a job).

    4. Psychological factors, not explicitly mentioned, that may have consciously or unconsciously influenced a protagonist (e.g., personal dislike).

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  7. Weird thing with the commenting system today, all my posts seem to be doubled...

    Arggh! At the end of your post, you wrote: " In case you missed it...", and whaddya know, I missed it! And wrote a whole comment based on that. Still, I think some of what I wrote might still contribute to the discussion, so herewith the corrected comment.

    Somewhere about the midpoint of this series, I asked for a definition of the Symmetry Principle. We've seen a few hints of one, along the way:

    1. Schaffer's interview offers a precis of The Fallacy: "That's to explain the truth one way, that's to say to explain what we think is so one way, and to explain what we don't think is so a completely different way", and a prescription for its cure: "it still seems to me, that people in social groups build their knowledge like they build other institutions, and you should analyze how they do that the way you analyze the institutions people build."

    2. I offered this formulation (called symm-2): "In examining any historical debate, we should ignore present-day views on which side was right, and apply equal standards to the evidence and motivations we ascribe to each side."

    3. In "How (not) to bring STS to the masses", you suggested this version: "In general, the truth-value of a past scientist's belief is a poor guide to the reasons they had for holding that belief."

    4. We have a subheading in this post: "Truth/falsity is not good evidence for good/bad reasons (Symmetry Principle)".

    5. Under the subheading (4), we have an echo of (3): "the truth-value of a belief is not a good guide to the motivations of the believer." Removing the word "not" then produces The Fallacy, and the recognition that The Fallacy is fallacious constitutes the Symmetry Principle.

    6. And finally, the Official Definition: "the twin claims that the truth of a belief is not good evidence that the believer had bad reasons for holding it, and that the falsity of a belief is not good evidence that the believer had good reasons for holding it."

    I have to wonder if you really meant to write (6) as it stands. Perhaps "good" and "bad" should be interchanged somewhere? (3)-(5) all urge us to guard against ascribing only good reasons to "correct" theories and only bad reasons to "incorrect" theories. (6) seems to do the opposite.

  8. Hi Michael,

    Thanks for these probing replies. And thanks for curating your madly replicating posts (I have no idea what went wrong, but experience shows that this sort of glitch tends to vanish as abruptly as it appears).

    1) The Schaffer quote makes a good endnote to this post. I don't want to put too much weight on the interview, since I am squeamish about holding anyone to what they say in an off-the-cuff answer to a journalist. Still, as per my first post in this series (, I do not think any historians of science have committed exactly the error that Schaffer seems to attribute to them in the first paragraph you quote.

    The second paragraph is another matter. Is Schaffer saying that social institutions are more important than cognitive factors in explaining how controversies pan out? Or is he just saying that these two kinds of explanation are on a par? And is he talking about social institutions as preconditions of scientists holding any theories at all, or rather as forces that tip the balance in favour of theory X rather than its rival (as per the distinction I mentioned under the Exclusion Principle in the above post)? Without an answer to those questions, I don't know whether the paragraph is an example of Social Constructivism or not.

    2) Yes, the "good/bad reasons" distinction opens up a can of worms. My defence is that anyone who endorses the symmetry principle--in whatever form--has to deal with the same writhing mess of complications. And I don't know any historians of science who completely reject the symmetry principle. So we're all in the same boat (or can).

    Having said that, your classification of reasons is a big help. No, there is not really a standard terminology in the field; but the good/bad distinction is truly idiosyncratic, and I would not use it if I did not think it were tied to the error that the Symmetry Principle protects us against. By that criterion, only type 1 would qualify as "good" reasons; and of those, only the arguments made in good faith. Only these reasons are such that we are tempted to invoke them to explain true beliefs. Why? Because we feel that they are the kind of reasons that will generate many true beliefs in the long run.

    3) You're right, I shot myself in the foot with the Official Definition. I've changed the text in the post so that it says what I mean, rather than the opposite of what I mean.

    You may have sensed my indecision over the words "guide" and "evidence." I began with the former, but now I prefer the latter. The reason is that I want to leave open the possibility that truth-value is, in fact, a good guide to motivation. That is, it may be that there is a strong historical association between true beliefs and good reasons, and between false beliefs and bad reasons. Even if this is so, however, we do not *know* that it is so. And as long as we do not know, we cannot use truth as evidence for good reasons, or falsity as evidence for bad reasons. So the advantage of using "evidence" rather than "guide" is that it is strong enough to make the key point but no stronger.

    1. Thanks for your reply.

      Good/bad reasons: I confess to a touch of uneasiness at drawing the line between (1) and (2), because of the whiff of presentism. Perhaps you can elaborate in your next post.

      What Schaffer meant: My knowledge of Schaffer's work comes mostly from Ether Wave Propaganda, so I'll wait for Will to weigh in.

    2. On good and bad reasons: yes, it would be presentist to express judgements like (1) in a historical book or article. But the point of the Symmetry Principle is precisely that such judgements *shouldn't* inform our books and articles. Or at least, they should not guide our decisions about what kind of explanation we apply to past beliefs. (I have argued in earlier posts in this series that those judgements can legitimately enter our historical explanations in other ways).