Whinging about conditionalization 
Subjective Bayesianism as it is often employed in philosophy of science consists of three commitments:
PSYCH (the psychological bit) An agent's degrees of belief can be represented as a real number for each proposition of the language.

SYNCH (the synchronic bit) An agent's degrees of belief at a time ought to obey the axioms of probability.

DIACH (the diachronic bit) An agent's degrees of belief should be updated over time by conditionalization.

As an example of DIACH, suppose that P1 is the probability function representing your beliefs before learning some evidence E and that P2 is the function afterwards. After learning E, you believe it; so P2(E)=1. For another hypothesis H, you should change your degree of belief in H to your prior degree of belief in H given E; that is P2(E)=P1(H|E). There is a general probability kinematics for cases in which your learning changes your degree of belief in but does not make you certain of E; often it's called Jeffrey conditionalization.

Colin Howson and Peter Urbach, in ch 6 of Scientific Reasoning, argue that violating SYNCH makes one inconsistent but that violating DIACH does not. They argue by constructing a case in which you are imagined to consistently violate DIACH. I'll summarize a streamlined version of the case before whinging about their argument.

Let P1, P2 be your successive degrees of belief. You believe some claim H for legitimate reasons: P1(H)=1. You suspect, however, that you have a brain lesion such that you will be less confident of H later on. Let E be the propostion 'P2(H)=1/2'. You suspect now that, because of the brain lesion, E will be true. Yet you think that E does not indicate any legitimate reason to doubt H. It will just be because you are overcome by vapors of black bile. As such, P1(H|E)=1. That is, you are presently confident of H even supposing that E turns out to be true (and you later lose confidence in H.)

Now the brain lesion does its work, and P2 is your new credence function. You are now uncertain of H: P2(H)=1/2. This is just the state of affairs represented by E, and you are aware of it, so P2(E)=1. If you kept your conditional probabilities fixed, as DIACH demands, then P1(H|E)=P2(H|E)=1. Yet it follows from the other values and rules of probability that P2(H|E)=1/2, so DIACH leads to a violation of SYNCH. Violating SYNCH would be inconsistent, so consistency demands violating DIACH.

That's the argument.

The brain lesion in this example seems like too much of a philosophers' contrivance, but I'll let that slide for a moment. Note, however, that the lesion makes it impossible to obey DIACH at all in this case. Given that you have prior P1(H|E)=1 and that you learn E, you should have posterior P2(H)=1. The lesion stops you from drawing that conclusion.

You can still obey SYNCH by adjusting P2(H|E)=1/2, but that does not seem like much of a victory. You would remain consistent, and so in that limited sense rational, but you would still be apportioning your belief in a vicious way. Your organic condition would have condemned you to a kind of irrationality, even if not inconsistency, and violation of DIACH would be symptomatic.

Moreover, there is a kind of legerdemain involved in conditionalizing on your present degrees of belief. As Richard Moran has argued, there is an important difference between third-person ascription (judging whether Steve believes H, for example) and first-person ascription (judging whether you believe H). The former involves considering Steve's behavior. The latter involves considering the evidence for and against H. You can ask the former question about yourself up until now. You ask the latter when you deliberate whether you now and henceforth shall believe H.

In the case given above, is your deliberation of the third-person or the first-person kind?

If it is third personal, then you must conclude that P2(H|E)=1/2. All of your behavior will indicate that, because it indicates P2(H)=1/2 and P2(E)=1. But, from the third-person standpoint, one must conclude that this configuration of belief is the irrational result of a bad brain.

If it is first personal, then it is nonsense to represent your reflection in terms of P2(H|E). E is itself a claim about P2. You must ask yourself, instead, that evidence suggests that H could be concluded from E. In effect, you are deliberating on what P3(H|E) ought to be. It is unclear how this deliberation would or should go, because the gedanken lesion is so underspecified that we don't know how or even if it constrains P3.

The subjectivist might object that it is spurious to call the violation of DIACH in this case irrational, because there is no bell that goes off telling you that your change of belief is vicious. Yet the subjective Bayesian typically does not specify which belief changes count as observations. If we consider purely your first-person point of view and treat DIACH as a rational constraint, then your spontaneous change from believing H P(H)=1 to not believing it P(H)=1/2 just is the learning that happens in this case. You ought to conditionalize on this new piece of evidence, using the full probability kinematics.

(Actually, the usual framework doesn't allow you to renege on beliefs once they are set to probability 1. But that is incidental to the point here. The case will suffice for H&U's argument, if at all, supposing any value for P1(H) that is distinct from P2(H).)

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The world is full of strata 
As Greg noted recently, there are no real measures of scholarly impact for philosophy journals. The blog Brains links to a recent effort by the European Science Foundation to provide such a measure. (I encountered the Brains entry via Brian Leiter's blog.) Various journals in philosophy and science studies are ranked A, B, and C. These lists are meant to represent the exposure and stature of the journals.

The lists are available as PDFs: philosophy and HPS.

The ESF FAQ offers several caveats: These are not intended to be rankings of journal quality. C ranked journals might still be quite influential within a region or scholarly niche. The rankings may be used to judge programs or institutions, but should not be used to judge individual scholars.

One wonders whether people will mind these caveats, however. Especially to an American, A, B, and C look like grades of quality. (Although I know that students are given numbers instead of letter grades in parts of Europe, I'm not sure whether letter grades are an exclusively American affectation.) Regardless, there is a tendency to overinterpret rankings when there are no other rankings available.

As an analogy, consider Leiter's Philosophical Gourmet Report. It is an influential ranking of graduate departments, but it is specifically a ranking of the research stature of the faculty within such departments. Nevertheless, it is used much more broadly than that-- largely because there is no comparable way of explicitly comparing graduate programs or philosophy departments.

The methodology of the Gourmet Report has been revised in recent iterations, and I will grant for the sake of discussion that it is now a decent instrument for measuring what it claims to measure. However, its influence was waxing even before its methodology had been honed. And even an accurate instrument can be used incorrectly. Consider some examples. (1) The tendency to take the rankings as judgments of department quality may lead job candidates to treat any ranked department as being better than an unranked department. A job at a first-rate liberal arts college might still have much to recommend it over a job at a school near the bottom of the list, but liberal arts colleges are not even eligible for the list. (2) It is an all too common fallacy to judge a philosopher by the prestige of their institution rather than on the basis of their own work. This does not require explicit rankings, but it is perhaps abetted by them.

Leiter offers such caveats, of course-- just as the FAQ for the ESF journal ratings explains that they are not ratings of quality. Yet a straight-forward rating is an appealing thing. Once we've got one, especially when there is no other instrument at hand, it is tempting to use it too widely.

Once you've got a hammer, the world is full of nails. Once you have a ranking instrument, the world is full of strata.

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Ruminations on fecundity 
Philosophers of science who argue over the virtues of theories typically concentrate on fit with observation, novel prediction, support for intervention, explanation, and unification. For each, there are arguments that it is truth-indicative, that it is not, that it marks a theory worth accepting, that it does not, and so on. Philosophers have had less to say about fecundity, the virtue a theory has when it gives us some sense of what to do next in enquiry. Obviously, scientists can make no use whatsoever of a theory that gives them no sense of what they might do next. The remainder of this post provides some almost connected ruminations on the subject.

Lakatos' Methodology of Scientific Research Programmes is a notable exception to philosophers' neglect of fecundity. (I have the affectation of using Lakatos' British spelling of "programme" to distinguish research programmes in a Lakatosian sense from more quotidian programs.)

Consider, as an example, research into the influence of hormones on development; what Helen Longino dubs the linear-hormonal model (LH). The programme "can continue to generate studies that are used to support microhypotheses about the etiology of particular forms of behavior that are consistent with [its] broader model." (For references, see Hormone Research as an Exemplar of Underdetermination.) Study after study can observe a correlation between prenatal hormone levels and gender-linked juvenile behavior. Different populations and data sets may be used, and so in some sense the programme suggests further research. Yet the programme dwells on observations of superficial phenomena, accumulating similar results insufficient to underwrite practitioners' claims about brain development. The programme's further direction doesn't seem to get anywhere.

In Lakatos' jargon, a research programme is theoretically degenerating if it does not yield any new testable predictions and empirically degenerating if its predictions turn out to be false.

One might defend the LH programme: Its research does make predictions and those predictions are often true, so it is both theoretically and empirically progressive (i.e., not degenerating.)

However, the LH programme only makes the conservative prediction that an observed correlation between two variables will continue in further instances. The predictions of a progressive research programme should be novel and unexpected, so LH is either somewhat degenerating or only minimally progressive (depending on how you want to spin it.) Unfortunately, surprisingness is most naturally treated as a psychological notion. This would lead us to say that jumpy, unimaginative scientists (who are surprised by banal predictions) will be judged to enjoy more progress than imperturbable scientists (who are surprised by nothing.)

The LH programme offers a kind of pathological fecundity, but are there any scientific research programmes that lack even that sliver of the virtue?

A clear example, I think, is so-called Intelligent Design theory. It is deliberately constructed so as to be incompatible with the research programme of evolutionary biology but to stop short of actually describing the alleged designer. It makes some predictions, perhaps, but not ones that can guide any sort of research programme.

A search of the blog reminds me that I have discussed these issues before, a propos of demarcation and pragmatism. As a slight tangent, I think this is an advantage of having a blog: If I had merely thought those things, I would have forgotten irretrievably. If I had written notes to myself on scraps of paper, they would either be buried in a file cabinet or thrown away long ago. Moreover (as I pointed out in the last post) notes to myself would have been more elliptical than the blog post. Even if I had exhumed them, it might have required some effort even for me to reconstruct what I had meant.

I am not certain how to draw these strands together, but during last Summer's reading group I discovered this relevant passage in Dewey's Logic:
The history of science, as an exemplification of the method of inquiry, shows that the verifiability (as positivism understands it) of hypotheses is not nearly as important as is their directive power. As a broad statement, no important scientific hypothesis has ever been verified in the form in which it was originally presented nor without very considerable revisions and modifications. The justification of such hypotheses has lain in their power to direct new orders of experimental observation and to open up new problems and fields of subject matter. In doing these things, they have not only provided new facts but have often radically altered what were previously taken to be facts. [p. 519]
To my knowledge, Dewey's point here was not directly influential on later philosophers and historians who said similar things. Thomas Kuhn (who listed fecundity among the scientific values) and Martin Rudwick (who has often emphasized the fact that a victorious theory typically arises from attempts to develop earlier theories) probably had not read this passage in Dewey. (This is a safe bet, because almost no one read Dewey's Logic.)

As a final note, I should say that the word 'fecundity' has a strange resonance for me. My homepage and e-mail are hosted at fecundity.com, a domain I have owned since 1999. I bought hosting and my own domain just so that I could toy with writing CGIs, an activity forbidden on the university servers. I had first encountered the word 'fecundity' years before when reading Jeremy Bentham. This gave it a strange association with the internet, since the live webcam of Jeremy Bentham's mummified body was one of the cool things on the net back then. The word has a nice sound to it, and the connection motivated one of the first banner ads I made for the site:

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Burst culture and the academic blog 
Warren Ellis calls blog-writing burst culture, and he argues that it is no substitute for old school, long form writing. Wil Wheaton complains that immersion in burst culture screws up his ability to write slower-paced prose. Wheaton is talking about narrative writing, but I am curious about this parallel question: Does blog writing lead to differences in the form and style of the philosophy?

Surely blogs themselves tend to be telegraphic. One might therefore suspect that philosophers who write blogs are primed to be more telegraphic when writing papers and books.

My experience is the opposite. Writing a blog post requires me to fill out more of the details than taking notes or scribbling down ideas. I am forced to think through the information that needs to be presented in order for my point to make any sense; in writing notes to myself, I can presume more and write less.

The result is that I sometimes blog ideas in ways that fit nicely into papers. My latest draft builds on posts about scientific significance, although admittedly I had been wrestling with these ideas before. My Wikipedia paper is a clearer case. It began as blog yammerings and would not have been written without them.

Also, blogging helps me unclog my analytic writing. I find that taking morsel sized ideas and setting them as blog posts puts me in the state of mind to write. It's like the little vamp that a jazz band plays when warming up, before launching into a set.

[I lack a segue to the next point, so (in true burst culture fashion) I continue without one.]

There is some debate among academic bloggers about how blogging should count. There are several basic positions. 1. Blogging is research. This suggests that we should devise some way of measuring the impact factor of academic blogs. 2. Blogging is a kind of outreach, making research and results available to a broader audience. 3. Blogging is professional service, like refereeing papers and organizing conferences. 4. Blogging is a hobby and should count for nothing.

Often, these debates are a bit too essentialist. Different answers fit different blogs.

Much of Janet Stemwedel's blogging strikes me as public outreach. It is addresses issues of scientific integrity and has an audience that includes many non-philosophers. (Answer 2.)

The non-political part of Brian Leiter's blogging strikes me as professional service. It provides news and commentary on developments within academic philosophy. (Answer 3.) The political part, which he has muzzled recently, strikes me as activism. (Although not exactly a 'hobby', it is not part of his role as an academic philosopher. So answer 4.)

For my own part: I do other stuff on the web that really is just an irrelevant hobby, but blogging is part of my doing philosophy. Nevertheless, I would not want my blog output to be weighed on the same balance as my published papers. If I let a month go by without a post, I don't want to feel the reigns of the tenure-horse slipping through my fingers.

This is only to consider three philosopher-bloggers. Academics in other disciplines have different blogging potential; it is hard to imagine a chemist's blog that would count as anything like chemistry research. In sum, expecting academic blogs to count all in the same way seems wrong-headed.

[Some nice conclusion belongs here, tying this back to the 'burst culture' thing with which I began.]

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Ye olde curiosity shoppe 
Yesterday, I put a draft paper about scientific significance on-line. It is directed largely at tensions in Philip Kitcher's Science, Truth, and Democracy.

For anyone keeping count, this is the second time I've written a paper in part because of ideas that percolated here in the blog.

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