Yesterday I defended my dissertation. I wanted to thank, in this very small but nonetheless public space, all the folks here who helped me along with the dissertation: John Earman and Nuel Belnap, who served on my committee, Tom Ricketts, who unfortunately joined the Pittsburgh department a little too late to be on my official committee, but still read dissertation chapters with a fine-toothed comb, and talked to me about them -- and job-market issues -- for hours, Steve Awodey, who not only discussed Carnap with me innumerable times, but also helped me in the process of professionalization and acculturation into the circle of philosophers who study Carnap seriously, and finally my advisor, Laura Ruetsche, who not only gave me searching, insightful, and helpful comments at myriad points in the development of the dissertation project, but also helping me through the occasionally-panic-inducing job search process.
So, thanks to all -- I feel very lucky to have had the final years of my grad school career shaped by you. I hope other PhD students are as fortunate as I have been.
4/04/2006
Semantics and necessary truth
I have recently been reading, with great profit, Jason Stanley's draft manuscript Philosophy of Language in the Twentieth Century, forthcoming in the Routledge Guide to Twentieth Century Philosophy. The paper's synoptic scope matches the ambitious title.
I'm curious about one relatively small claim Jason makes. On MS p.17, he says:
Here's my worry: as a preliminary, recall (as Tarski taught us) that semantic vocabulary should always be indexed to a particular language -- e.g., we must say 'is a true sentence of English' or 'x refers to y in Farsi' etc. in the full statement of sentences like (7). But then I am not so sure that such sentences are not true in all possible worlds. Is it really the case that, in English, "is smart" could have expressed the property of being from Mars? We specify a particular language (in part) by specifying the semantic values of the words of that language (at least, if we are not proceeding purely formally/ proof-theoretically). Wouldn't we be speaking another language at that point, that was similar to English, but not the same?
My intuitions lean towards saying that this would not be English, but those intuitions aren't firm. I think the question boils down to: "Is 'English' a rigid designator (i.e., does 'English' refer to the same thing(s) in all possible worlds)?", but I'm not sure about that, either. Which way do your intuitions run?
I'm curious about one relatively small claim Jason makes. On MS p.17, he says:
intuitively an instance of Tarski's schema T [GF-A: '...' is a true sentence if and only iff ...] such as (7) is not a necessary truth at all:This certainly has (as Stanley says) an "intuitive" ring. But now I'm not sure it's correct.
(7) "Bill Clinton is smart" is a true sentence if and only if Bill Clinton is smart.
(7) is not a necessary truth, because "Bill Clinton is smart" could have meant something other than it does. For example, "is smart" could have expressed the property of being from Mars, in which case (7) would be false.
Here's my worry: as a preliminary, recall (as Tarski taught us) that semantic vocabulary should always be indexed to a particular language -- e.g., we must say 'is a true sentence of English' or 'x refers to y in Farsi' etc. in the full statement of sentences like (7). But then I am not so sure that such sentences are not true in all possible worlds. Is it really the case that, in English, "is smart" could have expressed the property of being from Mars? We specify a particular language (in part) by specifying the semantic values of the words of that language (at least, if we are not proceeding purely formally/ proof-theoretically). Wouldn't we be speaking another language at that point, that was similar to English, but not the same?
My intuitions lean towards saying that this would not be English, but those intuitions aren't firm. I think the question boils down to: "Is 'English' a rigid designator (i.e., does 'English' refer to the same thing(s) in all possible worlds)?", but I'm not sure about that, either. Which way do your intuitions run?
4/03/2006
Tarski, Quine, and logical truth
The following must have been addressed already in the literature, but I'm going to mention it anyway--perhaps a better-informed reader can point me in the direction of the relevant research. W.V.O. Quine offers the following characterization of logical truth:
Now some historical questions: did Quine think his condition was sufficient, or just necessary? (I quickly checked "Truth by Convention," and I didn't find any conclusive evidence that he considered it sufficient.) If Quine does consider this a proper definition of logical truth, how does he/ would he answer Tarski's objection? -- and/or why doesn't Quine simply adopt Tarski's definition of logical truth, viz. 'truth in all models'?
(You might think Tarski's objection shouldn't count for much, since I used a very contrived language to make the point against Quine. In Tarski's defense, however, (a) assuming that every object has a name in our language also seems somewhat artificial, and (b) Tarski proved (elsewhere) that a single language cannot contain names for all (sets of) real numbers (See "On Definable Sets of Real Numbers," reprinted in Logic, Semantics, Metamathematics).)
The logical truths are those true sentences which involve only logical words essentially. What this means is that any other words, though they may also occur in a logical truth (as witness 'Brutus,' 'kill,' and 'Caesar' in 'Brutus killed or did not kill Caesar'), can be varied at will without engendering falsity. ("Carnap and Logical Truth," §2)All I wanted to mention here is that Alfred Tarski had already shown, in 1936's "On the Concept of Logical Consequence," that Quine's characterization is a necessary condition for a sentence to be a logical truth, but not a sufficient one. For example, if one is using an impoverished language that (i) only has proper names for things over five feet tall, and (ii) only has predicates applying only to things over five feet tall, then the sentence 'George W. Bush is over five feet tall' will be a logical truth -- because no matter what name from this impoverished language we substitute for 'George W. Bush' or what predicate we substitute for 'over 5 feet tall' in this sentence, the resulting sentence will be true.
Now some historical questions: did Quine think his condition was sufficient, or just necessary? (I quickly checked "Truth by Convention," and I didn't find any conclusive evidence that he considered it sufficient.) If Quine does consider this a proper definition of logical truth, how does he/ would he answer Tarski's objection? -- and/or why doesn't Quine simply adopt Tarski's definition of logical truth, viz. 'truth in all models'?
(You might think Tarski's objection shouldn't count for much, since I used a very contrived language to make the point against Quine. In Tarski's defense, however, (a) assuming that every object has a name in our language also seems somewhat artificial, and (b) Tarski proved (elsewhere) that a single language cannot contain names for all (sets of) real numbers (See "On Definable Sets of Real Numbers," reprinted in Logic, Semantics, Metamathematics).)
3/29/2006
Should a naturalist be a realist or not?
Unsurprisingly, the answer to the question in the title of this post depends on the details of what one takes 'naturalism' about science to mean. The shared conception of naturalism is something like 'There is no first philosophy' (I think Penny Maddy explicitly calls this her version of naturalism) -- that is, philosophy does not stand above or outside the sciences. "As in science, so in philosophy" is (one of) Bas van Fraassen's formulations.
Each of the following two quotes comes from a naturalist, but the first appeals to naturalism to justify realism (about mathematics), while the second appeals to naturalism in support of anti-realism (about science).
In his review of Charles Chihara's A Structuralist Account of Mathematics in Philosophia Mathematica 13 (2005), John Burgess writes:
The mathematician deals in proof. And proof is (at least a large part of) the source of mathematics' epistemic force. The number theorist (e.g.) assumes the existence of the integers and proves things about them; that's what she does qua mathematician. People with the proclivities of Burgess and van Fraassen would agree thus far, I think. But they part ways when we reach the question "Are there integers?" A Burgessite (if not John B. himslef) could say "If you're really going to defer to number theorists and their practice, they clearly take for granted the existence of the integers." A van-Fraassen-ite could instead say: "What gives mathematics its epistemic force and evidential weight is proof, and the number theorist has no proof of the existence of integers (or the set theorist of sets, etc.). Since there is no proof of the integers' existence forthcoming, asserting the existence of the integers (in some sense) goes beyond the evidential force of mathematics. Thus, a naturalist about mathematics should remain agnostic about the existence of numbers (unless there are other arguments forthcoming, not directly based on naturalism)."
Is there any way to decide between these forms of naturalism -- one which defers (for the most part) to the form and content of the sciences, and the other which defers only to the form? (Note: van Fraassen's Empirical Stance takes up this question, but this post is too long already to dig into his suggestions.)
Each of the following two quotes comes from a naturalist, but the first appeals to naturalism to justify realism (about mathematics), while the second appeals to naturalism in support of anti-realism (about science).
In his review of Charles Chihara's A Structuralist Account of Mathematics in Philosophia Mathematica 13 (2005), John Burgess writes:
"If you can't think how we could come justifiably to believe anything implyingCompare van Fraassen, in The Empirical Stance (2002):
(1) There are numbers.
then 'Don't think, look!' Look at how mathematicians come to accept
(2) There are numbers greater than 10^10 that are prime.
That's how one can come justifiably to believe something implying (1)." (p.87)
But [empiricism's] admiring attitude [towards science] is not directed so much to the content of the sciences as to their forms and practices of inquiry. Science is a paradigm of rational inquiry. ... But one may take it so while showing little deference to the content of any science per se.(p.63)Both Burgess and van Fraassen are naturalists about their respective disciplines (mathematics and empirical sciences) -- but they disagree on what the properly scientific reaction to questions like "Are there numbers?" and "Does science aim at truth or merely empirical adequacy?" is.
The mathematician deals in proof. And proof is (at least a large part of) the source of mathematics' epistemic force. The number theorist (e.g.) assumes the existence of the integers and proves things about them; that's what she does qua mathematician. People with the proclivities of Burgess and van Fraassen would agree thus far, I think. But they part ways when we reach the question "Are there integers?" A Burgessite (if not John B. himslef) could say "If you're really going to defer to number theorists and their practice, they clearly take for granted the existence of the integers." A van-Fraassen-ite could instead say: "What gives mathematics its epistemic force and evidential weight is proof, and the number theorist has no proof of the existence of integers (or the set theorist of sets, etc.). Since there is no proof of the integers' existence forthcoming, asserting the existence of the integers (in some sense) goes beyond the evidential force of mathematics. Thus, a naturalist about mathematics should remain agnostic about the existence of numbers (unless there are other arguments forthcoming, not directly based on naturalism)."
Is there any way to decide between these forms of naturalism -- one which defers (for the most part) to the form and content of the sciences, and the other which defers only to the form? (Note: van Fraassen's Empirical Stance takes up this question, but this post is too long already to dig into his suggestions.)
3/15/2006
Pessimistic induction + incommensurability = instrumentalism?
One popular formulation of Scientific Realism is: Mature scientific theories are (approximately) true.
One of the two main arguments against this claim is the so-called 'Pessimistic (Meta-)induction,' which is a very simple inductive argument from the history of science: Most (or even almost all) previously accepted, (apparently) mature scientific theories have been false -- even ones that were very predictively successful. Ptolemy's theory yielded very good predictions, but I think most people would shy away from saying 'It is approximately true that the Sun, other planets, and stars all rotate around a completely stationary Earth. So, since most previous scientific theories over the past centuries turned out to be false, our current theories will also probably turn out to be false. (There are many more niceties which I won't delve into here; an updated and sophisticated version of this kind of argument has been run by P. Kyle Stanford over the last few years.)
The kind of anti-realism suggested by the above argument is that the fundamental laws and claims of our scientific theories are (probably) false. But we could conceivably read the history of science differently. Many fundamental or revolutionary changes in science generate what Kuhn calls 'incommensurability': the fundamental worldview of the new theory is in some sense incompatible with that of the older theory -- the changes from the classical theories of space, time, and matter to the relativistic and quantum theories are supposed to be examples of such changes. Communication breaks down (in places) across the two worldviews, so that each side cannot fully understand what the other claims.
Cases of incommensurability (if any exist) could result in each side thinking the other is speaking incomprehensibly(or something like it), not merely that what the other side is saying is false in an ordinary, everyday way. An example from the transition from Newtonian to (special) relativistic mechanics may illustrate this: Suppose a Newtonian says 'The absolute velocity of particle p is 100 meters per second.' The relativistic physicist would (if she is a Strawsonian instead of a Russellian about definite descriptions) say such a sentence is neither true nor false -- because there is no such thing as absolute velocity. [A Russellian would judge it false.] If she merely said "That's false," the Newtonian physicist would (presumably) interpret that comment as 'Oh, she thinks p has some other absolute velocity besides 100 m/s; perhaps I should go back and re-measure.' To put the point in philosophical jargon: presuppositions differ between pre- and post-revolutionary science, and so the later science will view some claims of the earlier group as exhibiting presupposition failure, and therefore as lacking a truth-value, like the absolute velocity claim above. (Def.: A presupposes B = If B is false, then A is neither true nor false)
This leads us to a different kind of pessimistic induction: (many of) the fundamental theoretical claims of our current sciences probably lack a truth-value altogether, since past theories (such as Newtonian mechanics) have that feature. (If you want to call claims lacking truth-values 'meaningless,' feel free, but it is not necessary.) This is hard-core instrumentalism, a very unpopular view today; most modern anti-realists, following van Fraassen, think that all our scientific discourse is truth-valued (though we should be agnostic about the truth-value of claims about unobservable entities and processes). But this instrumentalism seems to be a natural outcome of (1) taking the graveyard of historical scientific theories seriously, (2) believing there is something like Kuhnian incommensurability, and (3) holding that incommensurability involves presupposition failure. And none of those three strike me as crazy.
Disclaimer: This argument has probably been suggested before, but I cannot recall seeing it anywhere.
One of the two main arguments against this claim is the so-called 'Pessimistic (Meta-)induction,' which is a very simple inductive argument from the history of science: Most (or even almost all) previously accepted, (apparently) mature scientific theories have been false -- even ones that were very predictively successful. Ptolemy's theory yielded very good predictions, but I think most people would shy away from saying 'It is approximately true that the Sun, other planets, and stars all rotate around a completely stationary Earth. So, since most previous scientific theories over the past centuries turned out to be false, our current theories will also probably turn out to be false. (There are many more niceties which I won't delve into here; an updated and sophisticated version of this kind of argument has been run by P. Kyle Stanford over the last few years.)
The kind of anti-realism suggested by the above argument is that the fundamental laws and claims of our scientific theories are (probably) false. But we could conceivably read the history of science differently. Many fundamental or revolutionary changes in science generate what Kuhn calls 'incommensurability': the fundamental worldview of the new theory is in some sense incompatible with that of the older theory -- the changes from the classical theories of space, time, and matter to the relativistic and quantum theories are supposed to be examples of such changes. Communication breaks down (in places) across the two worldviews, so that each side cannot fully understand what the other claims.
Cases of incommensurability (if any exist) could result in each side thinking the other is speaking incomprehensibly(or something like it), not merely that what the other side is saying is false in an ordinary, everyday way. An example from the transition from Newtonian to (special) relativistic mechanics may illustrate this: Suppose a Newtonian says 'The absolute velocity of particle p is 100 meters per second.' The relativistic physicist would (if she is a Strawsonian instead of a Russellian about definite descriptions) say such a sentence is neither true nor false -- because there is no such thing as absolute velocity. [A Russellian would judge it false.] If she merely said "That's false," the Newtonian physicist would (presumably) interpret that comment as 'Oh, she thinks p has some other absolute velocity besides 100 m/s; perhaps I should go back and re-measure.' To put the point in philosophical jargon: presuppositions differ between pre- and post-revolutionary science, and so the later science will view some claims of the earlier group as exhibiting presupposition failure, and therefore as lacking a truth-value, like the absolute velocity claim above. (Def.: A presupposes B = If B is false, then A is neither true nor false)
This leads us to a different kind of pessimistic induction: (many of) the fundamental theoretical claims of our current sciences probably lack a truth-value altogether, since past theories (such as Newtonian mechanics) have that feature. (If you want to call claims lacking truth-values 'meaningless,' feel free, but it is not necessary.) This is hard-core instrumentalism, a very unpopular view today; most modern anti-realists, following van Fraassen, think that all our scientific discourse is truth-valued (though we should be agnostic about the truth-value of claims about unobservable entities and processes). But this instrumentalism seems to be a natural outcome of (1) taking the graveyard of historical scientific theories seriously, (2) believing there is something like Kuhnian incommensurability, and (3) holding that incommensurability involves presupposition failure. And none of those three strike me as crazy.
Disclaimer: This argument has probably been suggested before, but I cannot recall seeing it anywhere.
3/10/2006
Want a job? Come to Pitt HPS
As some of you know, I am in the last stages (throes?) of my PhD program at the University of Pittsburgh, in the History and Philosophy of Science (HPS) department. For those who are not familiar with it, the department is relatively small: there are usually about 8-9 faculty whose primary appointment is in HPS, and about 30 or so graduate students.
In an average year, 1 to 3 people from my department go on the job market, and the department has had a very good placement record since I've been here: everyone who graduated from the program has gotten a tenure-track job, either straight out of grad school or after a 1-2 year post-doc. But this year, we had ten people go on the market, eight of them (myself included) for the first time. There was a lot of hand-wringing and worry, by students and faculty alike, about having so many HPS people on the market at one time. The demand for folks like us, who prove theorems in the foundations of quantum gravity or trace out the technical development of Galileo's kinematic theory, is just not as high as for people who work in ethics or epistemology.
I am now happy to report that all ten people have found good positions: 8 people are beginning tenure-track jobs, and the other two are taking enviable post-doc positions (including filling fellow-blogger Gillian Russell's old spot as Killiam fellow). I won't give the list of where everyone is headed, since I haven't asked their permission to broadcast that information to the three people who read this blog. But I grant myself permission to announce that I will be starting next fall as an assistant professor at UNLV (the University of Nevada-Las Vegas). It's a great position for me, in a department full of smart, sensible, and funny people. I'll probably blog in more detail soon about why I'm so excited about it -- but for starters, it was 70 degrees when I visited in January!
UPDATE: The Killam Fellow mentioned above will have a tenure-track position, though it is not yet determined where he will be yet. So 9 of 10 will start tenure-track jobs.
In an average year, 1 to 3 people from my department go on the job market, and the department has had a very good placement record since I've been here: everyone who graduated from the program has gotten a tenure-track job, either straight out of grad school or after a 1-2 year post-doc. But this year, we had ten people go on the market, eight of them (myself included) for the first time. There was a lot of hand-wringing and worry, by students and faculty alike, about having so many HPS people on the market at one time. The demand for folks like us, who prove theorems in the foundations of quantum gravity or trace out the technical development of Galileo's kinematic theory, is just not as high as for people who work in ethics or epistemology.
I am now happy to report that all ten people have found good positions: 8 people are beginning tenure-track jobs, and the other two are taking enviable post-doc positions (including filling fellow-blogger Gillian Russell's old spot as Killiam fellow). I won't give the list of where everyone is headed, since I haven't asked their permission to broadcast that information to the three people who read this blog. But I grant myself permission to announce that I will be starting next fall as an assistant professor at UNLV (the University of Nevada-Las Vegas). It's a great position for me, in a department full of smart, sensible, and funny people. I'll probably blog in more detail soon about why I'm so excited about it -- but for starters, it was 70 degrees when I visited in January!
UPDATE: The Killam Fellow mentioned above will have a tenure-track position, though it is not yet determined where he will be yet. So 9 of 10 will start tenure-track jobs.
2/22/2006
Quantum logic question
I've been thinking about quantum logic (QL) recently, and in particular about the usual semantics for 'or' in QL. I've become puzzled, and hopefully someone out there in the blogosphere can help me clear up my confusion.
For the uninitiated: In QL, propositions are represented by/ interpreted as subspaces in a Hilbert space -- including one-dimensional subspaces, i.e. rays. There are multiple ways of formulating in colloquial language what these subspaces are to represent (see final paragraph below), but (atomic) sentences are usually taken to have the form:
'The value of observable O is o1'
where 'observable' just means any physical quantity (e.g., position, momentum, energy, spin), and o1 is just a particular value (or range of values) of that observable. (E.g. 'The energy of this system is between 4 and 6 Joules.') Such sentences are true iff the state-vector of the system lies within the subspace.
Now, think of a particle P in a superposition of spin up and spin down along the y-axis. This particle's state is of course represented by a different vector (call it V_s) than particles in the spin-up state (represented by V_up), or particles in the spin-down (V_down) state. However, because the usual QL semantics assigns to 'p or q' the linear span, instead of the union, of the rays associated with p and q, the claim 'P is spin-up or P is spin-down' will be true -- because V_s is in the linear span of the spin-up ray and the spin-down ray. Each of the disjuncts is false, but the whole disjunction is true. (To me, this feature of QL is even more striking than the failure of the so-called distributive law, i.e., [p&(q or r)] iff [(p&q) or (p&r)], which commentators on QL tend to focus on.)
This seems intuitively wrong to me (or at least as 'wrong' as something can be in formal semantics). In 2-D Euclidean space, suppose we have a unit vector V at a 45-degree angle to the x-axis. I don't think anyone would consider the sentence 'V lies along the x-axis or V lies along the y-axis' to be true. V is not a unit vector on the x-axis or on the y-axis, but a distinct third thing. I don't see why we would change policies in the quantum case, which appears analogous to me.
So now I can ask my question: could we change the semantics for 'or' to avoid these apparent problems? In particular, in the usual semantics for quantum logic, why must all propositions be represented as subspaces on a Hilbert space? -- why not also allow subsets (which might not be closed under linear combinations)? For then we could allow 'or' to mean the union of rays, and 'P is spin-up or P is spin-down' will come out false.
One further note: some people (e.g. R.I.G. Hughes, "Quantum Logic and the Interpretation of Quantum Mechanics," PSA 1980) take the atomic QL propositions to have a different correlate in colloquial language. Instead of
'The value of observable O in system S is within o1,'
they take the subsets of Hilbert space to mean
'The result of a measurement operation for observable O in system S is within o1.'
Under this understanding, my above worries disappear -- for the result of a spin-y measurement surely will be either spin-up or spin-down. However, QL then becomes much less interesting, because it is just about measurement outcomes, instead of about these supremely odd things, superpositions.
For the uninitiated: In QL, propositions are represented by/ interpreted as subspaces in a Hilbert space -- including one-dimensional subspaces, i.e. rays. There are multiple ways of formulating in colloquial language what these subspaces are to represent (see final paragraph below), but (atomic) sentences are usually taken to have the form:
'The value of observable O is o1'
where 'observable' just means any physical quantity (e.g., position, momentum, energy, spin), and o1 is just a particular value (or range of values) of that observable. (E.g. 'The energy of this system is between 4 and 6 Joules.') Such sentences are true iff the state-vector of the system lies within the subspace.
Now, think of a particle P in a superposition of spin up and spin down along the y-axis. This particle's state is of course represented by a different vector (call it V_s) than particles in the spin-up state (represented by V_up), or particles in the spin-down (V_down) state. However, because the usual QL semantics assigns to 'p or q' the linear span, instead of the union, of the rays associated with p and q, the claim 'P is spin-up or P is spin-down' will be true -- because V_s is in the linear span of the spin-up ray and the spin-down ray. Each of the disjuncts is false, but the whole disjunction is true. (To me, this feature of QL is even more striking than the failure of the so-called distributive law, i.e., [p&(q or r)] iff [(p&q) or (p&r)], which commentators on QL tend to focus on.)
This seems intuitively wrong to me (or at least as 'wrong' as something can be in formal semantics). In 2-D Euclidean space, suppose we have a unit vector V at a 45-degree angle to the x-axis. I don't think anyone would consider the sentence 'V lies along the x-axis or V lies along the y-axis' to be true. V is not a unit vector on the x-axis or on the y-axis, but a distinct third thing. I don't see why we would change policies in the quantum case, which appears analogous to me.
So now I can ask my question: could we change the semantics for 'or' to avoid these apparent problems? In particular, in the usual semantics for quantum logic, why must all propositions be represented as subspaces on a Hilbert space? -- why not also allow subsets (which might not be closed under linear combinations)? For then we could allow 'or' to mean the union of rays, and 'P is spin-up or P is spin-down' will come out false.
One further note: some people (e.g. R.I.G. Hughes, "Quantum Logic and the Interpretation of Quantum Mechanics," PSA 1980) take the atomic QL propositions to have a different correlate in colloquial language. Instead of
'The value of observable O in system S is within o1,'
they take the subsets of Hilbert space to mean
'The result of a measurement operation for observable O in system S is within o1.'
Under this understanding, my above worries disappear -- for the result of a spin-y measurement surely will be either spin-up or spin-down. However, QL then becomes much less interesting, because it is just about measurement outcomes, instead of about these supremely odd things, superpositions.
2/13/2006
realism and the limits of scientific explanation
Long time, no blog. I finally got back a few days ago from the last of my visits to schools for final job interviews. It was very interesting and instructive to observe non-Pittsburgh philosophers in their native habitats. I should know by the end of this week where I'll be next year.
In lieu of an actual post, I am putting up the handout I used at a couple of my job talks. As a result, it looks programmatic/ bullet-pointy; but I tried condensing this into a normal post, and it was just far too long. If you can make out what's going on, I would really appreciate any feedback/ comments/ eviscerations from readers.
REALISM AND THE LIMITS OF SCIENTIFIC EXPLANATION
The argument
(P1) Scientists do not accept explanations that explain only one (type of) already accepted fact.
(P2) Scientific realism, as it appears in the no-miracles argument, explains only one type of already accepted fact (namely, the empirical adequacy or instrumental success of mature scientific theories).
(P3) Naturalistic philosophers of science “should employ no methods other than those used by the scientists themselves” (Psillos 1999, 78).
Therefore, naturalistic philosophers of science should not accept scientific realism as it appears in the no-miracles argument.
Explanation and defense of (P1)
Explanations that explain only one type of already accepted fact
(i) generate no new predictive content, even when conjoined with all relevant available background information [‘already accepted fact’], and
(ii) do not unify facts previously considered unrelated [‘only one type’].
Evidence for (P1): Scientists reject
- Virtus dormativa-style explanations
- ‘Vital forces’/ entelechies as explanations of developmental regularities
- Kepler’s explanation of the number of planets, and the ratios of distances between them, via the five perfect geometrical solids
- ‘Just-so stories’ in evolutionary biology
The no-miracles argument for scientific realism
Abductive inference schema
(1) p
(2) q is the best explanation of p
Therefore, q
No-miracles argument for scientific realism
(1) Mature scientific theories are predictively successful.
(2) The (approximate) truth of mature scientific theories best explains their predictive success.
Therefore, Mature scientific theories are (approximately) true.
Proponents of the no-miracles argument (Putnam, Boyd, Psillos) accept (P3), appealing to naturalism to justify their abductive inference to scientific realism. Putnam claims that scientific realism is “the only scientific explanation of the success of science” (1975, 73).
The argument for (P2): Scientific realism (i.e., the claim that mature scientific theories are approximately true)
(i) generates no new predictions,
(ii) unifies no apparently disparate facts, and
(iii) explains only one previously accepted fact, viz., science’s predictive success.
In lieu of an actual post, I am putting up the handout I used at a couple of my job talks. As a result, it looks programmatic/ bullet-pointy; but I tried condensing this into a normal post, and it was just far too long. If you can make out what's going on, I would really appreciate any feedback/ comments/ eviscerations from readers.
REALISM AND THE LIMITS OF SCIENTIFIC EXPLANATION
The argument
(P1) Scientists do not accept explanations that explain only one (type of) already accepted fact.
(P2) Scientific realism, as it appears in the no-miracles argument, explains only one type of already accepted fact (namely, the empirical adequacy or instrumental success of mature scientific theories).
(P3) Naturalistic philosophers of science “should employ no methods other than those used by the scientists themselves” (Psillos 1999, 78).
Therefore, naturalistic philosophers of science should not accept scientific realism as it appears in the no-miracles argument.
Explanation and defense of (P1)
Explanations that explain only one type of already accepted fact
(i) generate no new predictive content, even when conjoined with all relevant available background information [‘already accepted fact’], and
(ii) do not unify facts previously considered unrelated [‘only one type’].
Evidence for (P1): Scientists reject
- Virtus dormativa-style explanations
- ‘Vital forces’/ entelechies as explanations of developmental regularities
- Kepler’s explanation of the number of planets, and the ratios of distances between them, via the five perfect geometrical solids
- ‘Just-so stories’ in evolutionary biology
The no-miracles argument for scientific realism
Abductive inference schema
(1) p
(2) q is the best explanation of p
Therefore, q
No-miracles argument for scientific realism
(1) Mature scientific theories are predictively successful.
(2) The (approximate) truth of mature scientific theories best explains their predictive success.
Therefore, Mature scientific theories are (approximately) true.
Proponents of the no-miracles argument (Putnam, Boyd, Psillos) accept (P3), appealing to naturalism to justify their abductive inference to scientific realism. Putnam claims that scientific realism is “the only scientific explanation of the success of science” (1975, 73).
The argument for (P2): Scientific realism (i.e., the claim that mature scientific theories are approximately true)
(i) generates no new predictions,
(ii) unifies no apparently disparate facts, and
(iii) explains only one previously accepted fact, viz., science’s predictive success.
1/18/2006
philosophy of science in the blogosphere
I've recently noticed two new philosophy of science blogs on the internets worth following:
(1) Brains, by Gualtiero Piccinini, a recent grad of my department. As the title indicates, this leans towards cognitive science issues. This is the area of philosophy of science I know the least about, so I'm hoping keeping up with Gualtiero's blog will show me at least the tip of the iceberg.
(2) Words of Mass Dissemination, by Mickael Dickson, the current editor of the journal Philosophy of Science (which, from what I can tell, is widely agreed to be the leading North American periodical on philosophy of science). I have no idea how he'll have time to keep up with his editorial duties and make blog posts, but I certainly hope he does manage to juggle them both. (Though, it looks like posting has slowed down a bit recently.)
I apologize that it has been so long since my last real/ philosophically substantive post. Virtually all of my brain waves are currently dedicated to the job search, but I am working on a post about quantum logic (which, coincidentally, the above-mentioned Prof. Dickson has written on recently) that I hope will be up soon, once I figure out a couple more things.
(1) Brains, by Gualtiero Piccinini, a recent grad of my department. As the title indicates, this leans towards cognitive science issues. This is the area of philosophy of science I know the least about, so I'm hoping keeping up with Gualtiero's blog will show me at least the tip of the iceberg.
(2) Words of Mass Dissemination, by Mickael Dickson, the current editor of the journal Philosophy of Science (which, from what I can tell, is widely agreed to be the leading North American periodical on philosophy of science). I have no idea how he'll have time to keep up with his editorial duties and make blog posts, but I certainly hope he does manage to juggle them both. (Though, it looks like posting has slowed down a bit recently.)
I apologize that it has been so long since my last real/ philosophically substantive post. Virtually all of my brain waves are currently dedicated to the job search, but I am working on a post about quantum logic (which, coincidentally, the above-mentioned Prof. Dickson has written on recently) that I hope will be up soon, once I figure out a couple more things.
1/02/2006
A job candidate at the APA
I just returned to Pittsburgh from the American Philosophical Association meeting, where I had job interviews and gave a talk. This was my first trip to the APA, and many people had painted for me a picture of it as red in tooth and claw. There was a fair amount of anxiety in the air, but that's to be expected when 600 or so job-seekers are stuffed into a cage (I'm making up the number 600; there may have been more). But the whole affair was less psychologically traumatic than I had expected -- it was good to see old friends, all my interviews led to interesting and enlightening conversations (I never felt like I was being 'grilled,' much less attacked), and I met people I had only previously known in blogospheric form.
There was one difficulty with the conference that I did not expect: it was physically exhausting. I remember one faculty member who, a few months ago, advised job-seekers not to apply to every single job that they could, on the grounds that you don't want to have too many interviews at the APA. "Too many interviews?" -- I thought -- "How can you have too many?" Well, that person was right. I had a hard time keeping up my energy and focus for the interviews I had, and some people in my department had many more than me... I don't know how they did it.
I expect blogging to remain light here for the next couple of months, since I'm now entering the final stage of the job search process.
There was one difficulty with the conference that I did not expect: it was physically exhausting. I remember one faculty member who, a few months ago, advised job-seekers not to apply to every single job that they could, on the grounds that you don't want to have too many interviews at the APA. "Too many interviews?" -- I thought -- "How can you have too many?" Well, that person was right. I had a hard time keeping up my energy and focus for the interviews I had, and some people in my department had many more than me... I don't know how they did it.
I expect blogging to remain light here for the next couple of months, since I'm now entering the final stage of the job search process.
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