This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Notes on KAIL Chapter 10 11/15/06 (B.F.) This is a very long, technical, and difficult chapter. There is no hope of going through it all in one seminar. Instead, my comments (and Mikes comments) will focus on a few issues that are central to TWs discussion in the chapter. Lets begin by recalling TWs explication of E is evidence for H for S , which we have already discussed in our last meeting: (EV) E is evidence for H for S iff E is included in in S s body of evidence and Pr (H | E) > Pr (H) . Last week, we discussed the first component of (EV) the inclusion in S s body of evidence component. This week, we will focus on the second component the support as positive probabilistic dependence component. There are many important questions that must be answered in order to get a handle on the intended sense of this second component. Here are five: 1. What kind of probability function is TWs evidential probability function Pr? Pr (p) is clearly not S s actual degree of belief (credence) in p [Pr C a ]. For one thing, S s actual degrees of belief C a can be crazy (even incoherent ), and we want Pr to ground non-crazy claims about evidential support [although, its not entirely clear why we want this from a traditional epistemological point of view, which cares about full belief and knowledge see question (3), below, for further discussion of that issue]. Moreover, as we mentioned last week, if S s credence in either H or E happens to be extreme (zero or 1), then E and H cannot be positively dependent on C a . And, surely, S can actually have extreme credences in either E or H , for any E / H . As such, identifying Pr and C a would basically trivialize TWs support relation. Finally, TW wants his support relation to be objective , and identifying Pr and C a would make it patently subjective in a way TW doesnt want. Pr (p) is not even to be identified with the ideally rational or justified degree of belief (for S ) in p [Pr C j ]. TW says that this comes closer to what he has in mind with his evidential probability. For one thing, at least C j is objective in ways that C a is not. For instance, even if S happens to have extreme degree of belief in E or H , it might be that this is irrational or unjustified (given everything S knows). Moreover, C a might even be incoherent , whereas (presumably) C j cannot be. This gives C j a kind of objectivity (and also probative force) that seems to be required to undergird TWs objective support relation. However, TW wants to think of support as an objective relation between E and H [and some background corpus K see question (4) below]. But, if we identify Pr with C j , then we can still get undesirable verdicts about support, because an agent (albeit an ideally rational one) is getting between E and H . For instance, there may be cases in which C j (E) = 1, but we still want to say that...
View Full Document
This note was uploaded on 08/01/2008 for the course PHIL 290 taught by Professor Fitelson during the Fall '06 term at University of California, Berkeley.
- Fall '06