You are currently browsing the category archive for the ‘philosophy of science’ category.

In lecture three of Dynamics of Reason, Friedman addresses problems of relativism and rationality. This is needed since he leans so heavily on the picture of science coming out of Kuhn which on its own tends to invite charges of bad relativism. Read the rest of this entry »

Advertisements

The second lecture of Dynamics of Reason was much more substantive than the first. There were two main parts, a positive one and a negative one. Read the rest of this entry »

I started reading Michael Friedman’s Dynamics of Reason. The book is broken into two parts, the original lectures that form the basis for the book and things that came out of discussion of the lectures. I suppose I will reserve judgment on whether to read the latter bits till I’ve gotten through the main lectures. Read the rest of this entry »

I just read Inventing Temperature by Chang. It is, as may be expected from the title, a book on the history of temperature, focusing on the development of thermometry. Every chapter is divided into two parts: historical narrative and philosophical analysis. There are elements of each in both parts of the chapters though. I am going to comment on a few themes from the book. Read the rest of this entry »

There is a review of the Cambridge Companion to Logical Empiricism up on NDPR, written by Greg Frost-Arnold. The review makes the book sound fairly appealing. I wanted to comment on one thing. Towards the end there is a brief discussion of Richardson’s article which is on the relationship between Kuhn and the logical positivists. The question is why Structure was taken to be damaging to the positivists. The review notes that Structure of Scientific Revolutions appeared in the Vienna Circle’s encyclopedia, Carnap felt it fit with his own views, and none of the positivists published negative reviews. I would like to add something to that. Hempel’s 1966 Philosophy of Natural Science, an intro book in the same series as Quine’s Philosophy of Logic, argues for many similar things that Kuhn’s book does. There are differences enough, but, for example, some of what Hempel says about theory testing fits right in with what Kuhn says about paradigms. Of course, Hempel always couches things in terms of theories and doesn’t take as radical a view as Kuhn with respect to theory change, but there is a fair amount of alignment. In fact, there is much more than I antecedently thought going into Hempel’s book.

This is a short thing I wrote up for my philosophy of science class on Arthur Fine’s criticisms of van Fraassen’s position. I liked it, so I thought I’d share. Apparently in that seminar I didn’t make it pass the Scientific Image. The problem wasn’t solved, but I think I figured out what the problem is. Solving it will probably require figuring out why van Fraassen adopts the epistemological views he does. No mean task, that.

Read the rest of this entry »

This is a note I wrote on Salmon and Kitcher’s criticisms of van Fraassen’s view of explanation in the Scientific Image. It is a little flawed in that the defense I gave in the last third doesn’t mesh with what van Fraassen says in the book. I didn’t realize this when I wrote it though. Alas. Up until then I think it is not bad though.


In their article ”Van Fraassen on Explanation,” Salmon and Kitcher charge van Fraassen with presenting a theory of the pragmatics of explanation that fails to be a pragmatic theory of explanation. This is a hefty charge because van Fraassen denies that there is any sui generis explanatory virtue and defends this claim by providing a theory of explanation that purports to show how explanation is merely pragmatic. In this paper I will present two of Salmon and Kitcher’s objections to van Fraassen’s theory of explanation. I will then present replies on behalf of van Fraassen and argue that the criticisms do not undermine his project. I will close by presenting what seems correct in Salmon and Kitcher’s.

Briefly, van Fraassen sees explanations as answers to questions of the form ”Why is Pk the case?” A question Q in a given context can be identified with the triple (Pk, X,R), where Pk is the topic of the question, X is the contextually determined contrast class for Pk, and R is the contextually determined relevance relation. An explanation is an answer A to some ‘why’ question such that the A stands in R to (Pk, X). This makes van Fraassen’s theories of explanation and ‘why’ questions heavily dependent on context. This is explicit at the end of the chapter on explanation in the Scientific Image, where van Fraassen says, ”The discussion of explanation went wrong at the very beginning when explanation was conceived of as a relationship like description: a relation between theory and fact. Really it is a three-term relation, between theory, fact, and context.” Finally, for evaluating answers we need the background theory K and the part K(Q) that is salient to the question, both contextually dependent. With this background in mind, we will move to the objections to van Fraassen’s account.

I will focus on two of Salmon and Kitcher’s arguments against van Fraassen which deal with the relevance relations. One is that without any restrictions on what counts as a relevance relation, van Fraassen’s account of explanation reduces to triviality. The other is that without any restrictions on relevance relations, van Fraassen’s theory of explanation cannot rule out bad explanations without incorporating elements that undermine the claim that explanation is merely pragmatic.

According to Salmon and Kitcher, to reduce van Fraassen’s account to triviality, let Pk be a true proposition and X a set of propositions containing Pk and whose other elements are all false. Let R be {( A, ( Pk, X))}U S where S is any set of pairs of the form ( B, ( Y , Z)) where B and Y are propositions and Z is a set of propositions containing Y. Further, S cannot contain any pairs ( B, ( Y , Z)) such that B is true and ( Y , Z)=( Pk, X). Thus, for any true propositions A and Pk, there is a question Q such that A answers Q and Pk is the topic of Q. The conclusion is then: ”If explanations are answers to why-questions, then it follows that, for any pair of true propositions, there is a context in which the first is the (core of the) only explanation of the second.” Salmon and Kitcher think this is a reductio of van Fraassen’s position. They later go on to say that ”if van Fraassen’s account does not contain context-independent principles that preclude assigning [trivializing propositions] to K(Q)” then the above problems will arise. However, a closer examination of their argument will not support the reductio conclusion.

Salmon and Kitcher’s argument is not a reductio. Assuming that for each triple of topic, contrast class and relevance relation, there is a context that generates it, then all they have shown is that for each topic and explanation there is a context in which the latter explains the former. What they need for reductio is that for any topic and explanation, the relevance relation for a given context will be the one constructed above. If van Fraassen’s account said that any true proposition were an explanation for any question topic in a context, then it would be trivial. However, this is not the case. Some propositions will not explain some question topics in a given context although they could explain the topic in other contexts as the relevance relation of the context would be different. Thus, their reductio fails.

To see why their argument fails, it is helpful to note that the construction above does not invoke context. The contrast class X, the relevance relation R, and the background theory K are all determined by the context, not by the theorist. Formally van Fraassen leaves open the possibility that there are contexts such that for any true proposition they provide contrast classes and relevance relations such that the proposition explains the topic at hand, but this is, prima facie, not different than other theories of formal pragmatics. For example, David Kaplan’s theory of indexicals allows contexts in which the speaker is not at the location of the context or at the time or even in the world. These are in a way deviant contexts, but they are formally allowed. Kaplan suggests a natural way of restricting attention to non-deviant contexts. Turning back to van Fraassen’s theory, the possibility of unusual contexts is not a reductio of his position. The claim that there is no context in which a certain proposition would explain a given topic is quite strong, and various science fiction examples should provide inductive counterevidence to this claim.

One of Salmon and Kitcher’s criticisms of van Fraassen’s theory, and a possible reason why they do not mention context in formulating this objection, is that van Fraassen does not indicate any way in which the contrast class or the relevance relation are to be read off of the context. Looking again to Kaplan’s theory of indexicals, the formal contexts are quadruples ( cA,cT,cL,cW) of a speaker, a time, a location, and a world. It is fairly straightforward to figure out which formal context corresponds to which concrete context. The speaker cA will be the person talking and cT will be the time that person is talking. There are some complicating details, such as the extent of the location region. Ignoring these for the moment, the formal contexts are comprised of features that are easily read off of a concrete context. Returning to van Fraassen’s theory, a difference emerges. The contrast class and relevance relation are less straightforwardly read off the concrete situations. We will return to this point in the conclusion.

The other objection of Salmon and Kitcher to be discussed is that without any formal requirements on relevance relations, van Fraassen’s account allows bad explanations and the only way to rectify this makes explanation cease to be merely pragmatic. Their examples follow a pattern, so we will focus on their example of the astrological explanation of the date JFK was assassinated. The setup is that the contrast class is the set of propositions saying that JFK died each day in 1963 together with one saying that he survived 1963. The topic Pk is that he died on 11/22/63. Salmon and Kitcher stipulate that R is the relation of astrological relevance in which the answer stands to the contrast class and the topic. The answer consists of the conjunction of a true description D of the positions of the heavenly bodies, the proposition that if D then Pk, and the denial of everything in the contrast class except Pk. Salmon and Kitcher claim that van Fraassen’s theory says this is an explanation. Further, they think that van Fraassen cannot rule out the answer as being astrological because it invokes only facts that are part of the background theory K, i.e. astronomical facts. The only way out of this predicament, according to Salmon and Kitcher, is for van Fraassen to make it so that the relevance relations are not determined solely by merely subjective factors. They say, ”[van Fraassen] ought to be equally serious about showing that relevance is not completely determined by subjective factors. If we are talking about distributions and redistributions of personal probabilities, they must be subject to some kinds of standards or criteria…. To be scientifically acceptable, the redistribution of probabilities must involve differences in objective probabilities…” However, the move to more objective determinations of relevance and to objective probabilities introduces a non-pragmatic aspect into explanation, undermining van Fraassen’s claim that the explanatory virtue is just pragmatic.

Van Fraassen has two responses available, both rejecting excessive assumptions Salmon and Kitcher need for their arguments but to which van Fraassen is not committed. The first of these is that the background theory K includes only contemporary science, possibly with some additional factual information. Thus, in their example given above, the astronomical information is part of K but the astrological beliefs that the agents have and that make it a good explanation to them are not. This provides space for including suspect relations as relevance relations and getting around van Fraassen’s admonition that explanation shouldn’t rely on old wives’ tales. This allows enough space between K and the agents’ beliefs to allow Salmon and Kitcher’s problems to enter.

Van Fraassen should reject this construal of the background theory. Van Fraassen says, ”[K] is a factor in the context, since it depends on who the questioner and audience are.” Since it involves who the questioner and audience are, it would seem that van Fraassen means to include in K at least some of the beliefs of the agents in question. There is nothing to debar them from having mistaken or misguided beliefs, e.g. that astrology is true, which are part of K. Since K is not restricted to just contemporary science, van Fraassen has a response to their argument. He should deny that there are no astrological propositions in K. One of the agents involved in the exchange takes the explanation to be good precisely because they have astrological beliefs, so they should figure in K. If van Fraassen is entitled to claim that explanation should not be based on old wives’ tales then this will provide a way for him to rule the astrological explanation out as an explanation.

Van Fraassen has another response to Salmon and Kitcher’s argument. They assume further that the only solution to the problem is to make the relevance relations more objective and the probabilities involved into objective probabilities. This is a crucial step toward their conclusion that explanatory virtue is not just pragmatic. If the account must involve these objective features then it looks like explanation is not just pragmatic as it latches on to objective features of the world, above and beyond what van Fraassen thinks explanatory virtue involves.

The second response is to deny their crucial premises that the relevance relation and explanation must reflect objective probabilities. Constraints can be put on relevance which do not require tying it and explanation to objective probabilities. Van Fraassen says that ”observable is observable-to-us,” so it is to be expected that relevance would be relevance-to-us. The relevance relation should depend on K, which van Fraassen would allow to include the beliefs of the agents, as well as current science, to give content to van Fraassen’s claim that good explanation should use good science. This ties relevance to subjective factors, in the sense of relying on the subjects involved, possibly including personal probabilities. However, this need not count against it since the subjects and their beliefs are things science investigates, and so, in a sense, objective. Salmon and Kitcher have given no reason to demand more objectivity than that.

Without Salmon and Kitcher’s crucial premises concerning relevance, the pressure on van Fraassen’s theory to give up the claim that explanatory virtue is just pragmatic disappears. Salmon and Kitcher’s argument that van Fraassen’s theory requires explanation to have its own non-pragmatic virtue does not work against van Fraassen’s position. However, part of their criticism still stands.

At the heart of Salmon and Kitcher’s criticism is the charge that van Fraassen does not place any formal constraints on what constitutes a relevance relation while also claiming that not all relations between a proposition and a suitable ordered pair count as genuine relevance relations. This makes the relevance relation an unexplained explainer. It does a lot of the work in van Fraassen’s account of explanation, but there are no constraints on it or indications of what counts as a relevance relation.
As was said above, the relevance relations are less straightforwardly picked out of a concrete context than the speaker. Van Fraassen needs to give an account of how the context determines the relevance relation. Without such an account, van Fraassen has just shifted the focus from problems of explanation to problems of relevance.

While Salmon and Kitcher’s arguments do not work against van Fraassen in the way they claim, they do highlight demands on the relevance relation. The relevance relation should be tightly connected to the background theory. It should involve the beliefs and intentions of the agents involved in the explanation. Salmon and Kitcher supply a promising suggestion: isolating what look like relevance relations for different sciences at different times and generalizing from there. They have not shown that no account of relevance can be given and the pressure is on van Fraassen to supply such an account. If one cannot be given, then Salmon and Kitcher’s arguments will need to be reevaluated.

This is part of a paper I wrote that I liked. I’d prefer to break it up with most of the post under a fold, but I can’t get that functionality to work. If you have any advice, apart from Blogger’s help site, let me know and I’ll try to apply it here.

In his “Ontological Status of Observables,” Paul Churchland charges van Fraassen with being selectively skeptical about the unobservable. He draws our attention to a three-part distinction: (1) the observed, (2) the unobserved but observable, and (3) the unobservable. It would be crazy to only believe in (1), the actually observed things. Churchland thinks van Fraassen does not give a principled reason why his constructive empiricism says to believe in (1) and (2) but not (3). Without the principled distinction van Fraassen’s position is unstable since his reasons for not believing in (3) seem to apply also to (2). van Fraassen’s view either ends up coinciding with the crazy view or it looks like a form of realism. Churchland’s challenge can be posed as: what is the principled reason for believing in (2) but not (3)?
Read the rest of this entry »

I had a thought about how to motivate van Fraassen’s constructive empiricism (the view that we need only accept theories as empirically adequate, that is, believe what they say about observables and be agnostic about what they say about the unobservables) since anti-realist views can seem at times, unmotivated. The thought I had was that he is responding to Sellars’s Philosophy and the Scientific Image of Man. (Apologies for poor Sellars reconstruction.) In that essay, Sellars contrasts two images of man, the manifest and scientific images. The manifest one is, roughly, the commonsense conception of ourselves and the world. The scientific image is that which contemporary science gives us. I think it is roughly the difference Eddington finds between the everyday idea of tables and chairs and the view of them as composed mostly of empty space and composed of small, small particles and fields, etc. Sellars thinks that one important job of philosophy is to spell out the relation between the images. In the end, he says that they don’t need to be reconciled but that the manifest image needs to be joined to it. Sellars is also a realist of a rather extreme kind. He was also van Fraassen’s teacher at Pitt.

Now, my crazy idea is that van Fraassen’s constructive empiricism is an attempt to go the other way. It is an attempt incorporate the scientific image into the manifest. The manifest image seems to roughly correspond to the sort of thing that van Fraassen views as observable. Especially when viewed through empiricist lenses, the macroscopic level at which we normally find ourselves lends itself to being viewed as the world of the manifest image. Of course, van Fraassen doesn’t talk much about intentions and norms that Sellars’s manifest image also concerns itself with. Putting that aside for now, if one is agnostic about everything that is not observable, in van Fraassen’s sense, then one is agnostic about the traditional way of understanding the scientific image. Eddington gets just the manifest table. Constructive empiricism says to be agnostic about the scientific table. Everything science says about the observable is incorporated into our beliefs about the world of the manifest image. This seems like it is one way of cashing out the relation between the relation between the two images of man. The scientific image helps us to understand the manifest image, but we need only believe in the world of the manifest image.

I floated this in my philosophy of science class today. A couple of good points were raised against it. One is that apart from the title, van Fraassen doesn’t really mention the Sellars piece. Another is that what I have been calling the manifest image in van Fraassen’s book is somewhat different than the manifest image in Sellars’s essay. This is true, but it doesn’t seem that far from what you’d get if you took Sellars’s manifest image and tried to cast it in an empiricist vein. Depending how exactly observable gets spelled out in the end, this might not be tenable at all. I think that if the idea of observable is constrained to the roughly medium-sized macroscopic things and processes, then it is a possibility.

Author

Shawn Standefer, recent Ph.D. in philosophy from Pitt. (More about me)

Archives