11/19/2007

Can a widespread local realist be a global anti-realist?--and the preface paradox

I have been thinking about whether there might be something like the preface paradox in the scientific realism debates. There is now a distinction being drawn between local (or 'retail') realism, in which one argues for the truth of particular scientific theories (e.g. quantum mechanics) or the existence of particular scientific entities (e.g. quarks), on the one hand, and global (or 'wholesale') realism, in which one argues for the approximate truth (or referential success) of mature scientific theories in general.

What I'm wondering is whether it can be justified and/or rational to be an everywhere local realist (so QM is approximately true, and general relativity is approximately true, and population genetics is (approximately) true, etc.), but still be a global anti-realist -- say, because you place a lot of weight on the pessimistic induction on the history of science. Or, on the other hand, whether everywhere local realism really pushes us towards global realism.

I'm currently guessing that one CAN be an everywhere local realist without being a global one, for the following two reasons.
(1) One standard response to the preface paradox seems perhaps even more applicable here than in the preface case: while the author assigns a high probability to each individual assertion in her book, the probability of (p & q & r & ...) will be low.
(2) Also, although if A is true and B is true, then 'A and B' must be true, it seems to me that even if A is approximately true and B is approximately true, then 'A and B' need not be approximately true, for A and B could be contradictory (for example, the prima facie conflict between quantum mechanics and general relativity).

I'm happy to hear any reasons for the opposite view, viz. that widespread local realism pushes us towards global realism.

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11/12/2007

Azzouni and existential commitment in science

Last week Jody Azzouni was here to give a pair of talks: one about scientific theories, another about his view that English is inconsistent in a pretty radical way: Every sentence is both true and false. They were both a lot of fun, and Jody is a great interlocutor -- he kept both presentations relatively short and to the point to there'd be more time for questions and clarifications. I also have a soft spot for arguments defending unpopular ideas -- though I usually side with the orthodoxy, incredible ideas are often a bit more interesting to think about.

In the philosophy of science talk, Jody was building on his work on what he calls "thick epistemic access." His argument was that we should not (contra Quinean orthodoxy) have existential committment to all the posits of our current best scientific theory, but rather only those posits to which we have thick epistemic access. (See e.g. Kenny's post here for a quick but accurate description of thick v. thin v. ultrathin posits.)

I was wondering, however, whether the Quinean orthodoxy could be undermined in a more direct way that does not involve developing a whole epistemological apparatus to distinguish when we really do have strong evidence that such-and-such thing exists. (Such a question is certainly philosophically interesting and worthwhile, but it is likely to be complex and contentious in places.) Rather, I thought a simpler argument against the Quinean orthodoxy could go as follows:
Science is rife with idealizations -- some of which are ineliminable/ indispensible. But no one should be committed to such idealizations, since they are (almost by definition) deliberate and conscious falsifications in our theoretical account of the world. So existential commitment does not follow our best theories as well as Quine would like.

I realize that (1) there may sometimes be a legitimate question about whether a given bit of a theory is an idealization or not, but that just shows the term 'idealization' is vague -- all parties agree there is some idealization in science, even if they don't agree on every case. Also, (2) most examples of idealizations are not entities, but rather inaccurate properties (e.g., treating some body that we know to exist, like a point particle: we give an inaccurate description of the thing's dimensions). So maybe pointing out the widespread use of idealization will not create widespread problems for the Quinean orthodoxy.

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11/08/2007

Why no 'scientific wisdom'?

Why do people often talk about 'scientific knowledge,' but we virtually never hear of scientific wisdom? Is there something about the content or practices of science that precludes them from counting as wisdom? After all, if ‘wisdom’ means something in the neighborhood of 'deep, important, or fundamental knowledge,' it seems (to me at least) that science should be a paradigm case of wisdom.

Is this merely a linguistic quirk that bears no relation to the relationship between the nature of science and the nature of wisdom? Or does the fact that we rarely—if ever—speak of 'scientific wisdom' reveal something important? Here's a reason for thinking the latter.

Science provides instrumental reasons for action only, not categorical ones: If you want to build a nuclear bomb, then the atomic theory of matter will be an extremely useful tool in designing the weapon. It is no part of physics—or any other of the (paradigmatic?) (natural?) sciences—to say whether you should build a bomb or not. Science does not inform us as to what should be valued for its own sake, and not merely as a means to some further end (though e.g. sociology could inform us what is in fact valued). The information provided by science only helps us acquire those things we already value. This is closely related, if not identical, to the old saw that science tells us about facts, and says nothing about values. Wisdom, in contrast, is thought to involve knowledge of what should be valued for its own sake (as well as how best to achieve those ends). That is, wisdom can offer categorical reasons, whereas science provides instrumental ones only.

The literature on the relationship between science and values is both vast and contentious. However, I do not know of anyone who says that the content of theories in natural science includes claims about what is valuable for its own sake. (I could be oblivious and/or uninformed about this; I'm no expert in this sub-field.) It may be that the scientific ethos includes e.g. valuing truth over personal gain, but that’s not part of the general theory of relativity.

So now we have a reason why no one says 'scientific wisdom'—science is silent on what is valuable for its own sake, whereas wisdom requires this information.