It's tempting to interpret the Equal Weight View (EWV) as offering positive normative advice: 'when you disagree with someone you take to be an epistemic peer, you should split your credence equally between both your conclusions.' But this would lead to implausibly easy bootstrapping. (Two creationists don't become reasonable after splitting the difference between each other. It's just not true that what they (epistemically) ought to do is to give equal credence to both their unreasonable views. Rather, they ought to revise/reject their prior beliefs altogether. Cf. wide-scope oughts.) To avoid this problem, Adam Elga restates EWV merely as a constraint on perfect rationality. That is: if you fail to split your credence in this way, then you're making some rational error. But even if you satisfy the EWV constraint, you might be making some other, more egregious, error. So it doesn't follow that, all things considered, you ought to follow EWV.
Or consider Roger White's argument against imprecise credence. It shows that we're "irrational" (i.e. imperfectly rational) to have other than perfectly precise credence in any proposition. But given our cognitive limitations, I expect we'd do even worse if we tried to give a precise credence to every proposition under the sun.
The fact is, we're not ideal agents. We have no hope whatsoever of being perfectly rational. And this leads to the problem of second best. That is, attempts to conform to norms of ideal rationality may end up leading us even further away from that goal. What we really need are norms of non-ideal ("second best") rationality, that recognize that we will make rational errors, and so incorporate strategies for recovering from such errors. In other words, we need to know what to do in case we are in an irrational position to start with -- how can we revise our beliefs so as to make them less irrational? Bayesian updating and other rationality-preserving rules are no help at all when your initial belief state has no rationality to preserve.
[I'm sure this isn't an original observation. I know many moral and political philosophers are interested in non-ideal theory. I'm just less familiar with epistemology. Can any readers point me in the direction of epistemologists who work on non-ideal theory?]
Thursday, April 10, 2008
Rational Recovery
Saturday, April 05, 2008
Zombie Rationality
'Zombie' writes:
On Chalmers' view, wherein the 'psychophysical laws' are contingent, it seems that across possible worlds most brains like ours will be zombies or at least have 'associated' qualia that don't 'match' the information processing in the brain. So sophisticated brains proceeding according to ordinary standards of rationality should zombie-conclude that they probably are not conscious (as they don't have access to any non-material qualia), despite their zombie-perceptions of being conscious (shared by both zombie and non-zombie brains). Yet Chalmers thinks that in our actual world the psychophysical laws lead to conscious experience mirroring the information processing in the brain. So, upon hearing the argument, shouldn't Chalmers' brain zombie-conclude that it is probably a zombie brain, and 'phenomenal Chalmers' consciously think the same?
No. Conclusions are drawn by people, not brains. Standards of rationality likewise apply to agents and their beliefs, not to their physical components (brains and neural states) in isolation.
On my view, beliefs are partly constituted by phenomenal properties -- that's what gives them their representational content. Zombies don't have beliefs like we do. They exhibit all the same behaviour, and make all the same noises, but there's no meaning in it. It's not really about anything.
One might define a 'z-belief' as the functional (physical, dispositional) component of a belief. It's not so clear how to assign pseudo-contents to these z-beliefs, but I guess a reductionist may offer a stipulation of some kind: S has a z-belief that P iff S has such-and-such physical dispositions [e.g. 'S behaves as though P were true', or 'S has a brain state which covaries with evidence of P', or some such. See my essay 'What Behaviour is About' for a more sophisticated empirical approach to attributing "content".]
Presumably we're to suppose that whenever I really have the belief that P, my brain has the z-belief that P. But I doubt whether any such reduction can be given that perfectly mirrors my actual belief contents. (If epiphenomenalism is true, and qualia are partly determinative of belief content, then the physical facts underdetermine what it is that I believe. My inverted-spectrum duplicate has the same brain -- hence z-beliefs -- as me, but our phenomenal beliefs are very different. My 'red' is his 'blue', or whatever.)
There's a more fundamental problem, even if we grant the reductionist his impossibly fine-grained z-content. Let's grant - per impossibile - that my brain (and zombie twin) "z-believes that P" iff I believe that P. However, my brain (understood as a purely physical system, i.e. excluding its phenomenal properties) is in possession of only a subset of my total evidence. Qualia - the contents of experience - are among my evidence if anything is. But these phenomenal properties are not causally accessible to my neural processes. So the conclusion 'I am conscious' follows from my evidence, but not from the "information" available to my brain. One can be a rational person, or have a "rational" brain, but not both.
Now, it's pretty obvious that being a rational person is better than having a "rational brain" (insofar as the latter attribution is even meaningful). Brains are parts of people, and like any body part we really only care about it for how it can serve the whole person. If quick feet didn't make for a quick person, we wouldn't much care for the former. Similarly, a rationally desirable brain is one that makes for a rational person, with justified beliefs.
One could imagine a brain that is instead built in such a way that it tends to produce "z-justified" z-beliefs. What this means is that it tends to end up in physical states such that a conscious person in that physical state would have beliefs in line with the physically accessible subset of their evidence. When put like that, it becomes clearer that what we've really described here is a defective brain. Let's call it "z-rational", and reserve the term 'rational' for brains that give rise to rational people -- people whose beliefs are in line with their total evidence.
Here are two implications:
(1) A z-rational brain can be expected to have more true z-beliefs (across all possible worlds).
(2) A rational brain can be expected to yield more true beliefs.
Fortunately, my brain is rational rather than z-rational. Hopefully yours is too (otherwise, you're a defective agent). One might try to argue that there's something "wrong" with a brain that isn't z-rational, but I don't think that'll work. For one thing, since you're really just describing a physical state it's not clear that brains or z-beliefs are even open to this sort of normative assessment. Norms apply primarily to people, and to our organs only derivatively. What a well-functioning agent really needs is a brain that will make them rational, not z-rational. As suggested above, a z-rational brain is defective from the standpoint of contributing to the functioning of the whole person (which is the relevant standpoint against which to assess brains). Further, when you stop to think about what it really means to have 'z-rational z-beliefs', you see that there's not really anything significant (worth caring about) there.
Saturday, March 22, 2008
Knowledge as Sufficiently Safe Belief
Jack has been posting on epistemic closure principles. I know that I have hands. I also know that, if I have hands, then I'm not a (handless) brain in a vat (BIV). But, it's generally supposed, I can't know that I'm not a BIV.
Something weird's going on here. For an intuitive complaint, look at the abominable conjunctions:
# I know that I have hands, but I don't know that I'm not a handless BIV.
# (Expressed in assertion:) "I have hands, but I can't say whether I'm a handless BIV."
For a principled complaint, it makes no sense to think that I could have less epistemic warrant or evidence for the logically weaker claim. The other entails it. The worlds where I have hands are a proper subset of the worlds where I'm not a handless BIV. It's as silly as thinking that Linda is more likely to be a feminist bank teller than a bank teller.
My favoured solution is due to Keith DeRose. S's belief that P is epistemically safe precisely to the extent that certain possible worlds -- namely, those where S believes P falsely -- are distant. Degree of safety is the fundamental epistemic property, and it satisfies closure principles perfectly, as we should expect. I think I have hands, and I think I'm not a BIV, and the latter belief is at least as safe as the former. (You'd have to go out to at least as distant a possible world in order to find one where I hold the belief falsely.)
Why do closure principles seem to fail for knowledge, then? Simply because the standards for knowledge vary. Knowledge is belief that is sufficiently safe for our purposes. Whether a belief that's safe to degree N so qualifies is an open question, and one that will receive different answers in different contexts. Raising certain possibilities to salience will tend to raise the bar, requiring that the safety level of the belief extend to the possible worlds under consideration. Once the bar is raised so high, even our ordinarily safe beliefs will not qualify as "knowledge". Abominable conjunctions are thus avoided.
So we find that the apparent failure of closure is an artifact of our shifting standards. At the fundamental level, epistemic qualification (i.e., safety) transmits across entailments just fine.
Saturday, January 12, 2008
Are Contradictions So Bad?
Granting the law of non-contradiction, do we necessarily have reason to avoid holding inconsistent beliefs (as such)? If so, then our pre-existing beliefs, no matter how absurd, would 'bootstrap' reasons into existence. But that seems dubious: just because one believes that the world is 6000 years old, it does not follow that one has any reason whatsoever to refrain from believing that the world is over a billion years old. (One ought to revise the former belief instead!)
In 'The Myth of Instrumental Rationality', pp.20-1, Raz addresses the grounds of our lingering hostility to contradictions:
When we learn that there is a contradiction among our beliefs we learn (1) that some of our beliefs are false, and (2) that we hold some beliefs that if used together as premises in an argument may lead us astray in a special way [i.e. logical 'explosion']. Big deal! We hope that we all know that some of our beliefs are false anyway. And the risk that we will actually be led astray not by the logical implications of our false beliefs, but by their contradictory features, is, for all practical purposes, negligible...
To conclude: There is nothing wrong with holding contradictory beliefs as such, and the fact that one does is no reason to change one's beliefs. At most we could say that we should abandon our false beliefs. But that is so not because of the contradiction. Knowing that a set of propositions is contradictory has epistemic relevance: It tells us that the contradictory set contains a falsehood. It may be part of a case for believing that one particular proposition is false. But it is no such case by itself. Without such a case we have no reason to abandon any of them. For all we know, we may then abandon a true belief and remain with false ones. Nor do we have reason to suspend belief in all the propositions in the contradictory set. The cost, epistemic and otherwise, of doing so may be too great. That is why the logical paradoxes are rightly not generally taken as a reason to suspend our acceptance of the principles that generate them.
What do you think?
Epistemic Akrasia
Is it possible to be weak-willed in one's beliefs, i.e. to believe other than what one takes oneself to have most reason to believe? It seems not: the possibility of weak-willed action arises from the gap between one's reasoned conclusions and the intentions to act that may be formed on their basis. But there is normally no such gap or further step involved in belief formation: reasoning concludes in belief (i.e. judgment about what is the case), without any further role for the will.
Raz offers a different argument, in his 'Reasons: Practical and Adaptive', p.7:
because there is no possibility that the lesser reason for belief serves a concern which is not served better by the better reason there is no possibility of preferring to follow what one takes to be the lesser reason rather than the better one. The possibility of akrasia depends on the fact that belief that a practical reason is defeated by a better conflicting reason is consistent with belief that is serves a concern which the better reasons does not, and which can motivate one to follow it.
The thought here is that in practical cases, there is at least something to be said for acting on the lesser reason. If I can save either one life or two others, there's something appealing about the former option, even if the latter is better on balance. The former reason is outweighed, but not entirely defeated. Epistemic reasons, in contrast, seem to be defeated and not merely outweighed. As Raz puts it (p.6):
The weaker reasons are just less reliable guides to one and the same end [viz., truth]. There is no loss in dismissing a less reliable clue.
Or, in other words, practical reasons are pro tanto reasons, exerting some degree of force, whereas epistemic reasons are merely prima facie reasons -- liable on further examination to turn out to be no real reason at all.
But I wonder whether it is true that "there is no possibility that the lesser reason for belief serves a concern which is not served better by the better reason". Sure, epistemic reasons serve truth, but practical reasons may be thought to serve a monistic good (e.g. human welfare), and that doesn't prevent tradeoffs between different instances of this end. So let's consider a case where there are competing truths (analogous to the competing lives in our earlier example):
Suppose I am assessing two competing belief-sets or comprehensive theories/ideologies (T1 and T2) regarding some area of discourse D. Though both seem flawed, I am aware of no alternatives which are more coherent and plausible than these two, and can see no promising way to combine them. Further suppose that T1 seems on balance the better theory -- more likely to be true, or true in more of the sub-areas of D that matter. However, I nonetheless think that T2 is much more plausible regarding some specific sub-area Ds. I am so drawn to T2's account of Ds, that I end up accepting (believing?) T2 overall, even though I judge that I have more reason to believe T1.
Does that sound like a genuine case of epistemic akrasia?
Friday, October 26, 2007
Experimental Philosophy
If philosophers are going to appeal to facts about what seems "intuitive", should they first do empirical work to find out whether most folk actually share their intuition? So suggest the experimental philosophers. I'm skeptical, however. The epistemic force of an intuition depends on the coherence of the conceptual scheme that generates it. Philosophers are presumably better than layfolk at thinking clearly about philosophical concepts. So I don't really see that we have much to learn from their untutored intuitions. (Some complain that our intuitions are "corrupted" by theory - but mightn't this be better described as refinement?)
Doris and Stich (2005) 'As a Matter of Fact: Empirical Perspectives on Ethics' puts forward the case for experimental philosophy. Below, I reproduce my comments from a past (off-blog) discussion.
* * *
Insofar as philosophers are concerned with non-contingent matters, it seems that a priori analysis should suffice. Consider the internalist's question: is amoralism possible? We already have the challenge from Hume's imagined "sensible knave" -- what difference do real life psychopaths make? In either case, it seems like a question for conceptual analysis: given such and such a scenario, how are we to describe it? (Does the knave/psychopath really form moral judgments, or merely schmoral ones?)
Now, a central argument of the paper criticizes conceptual analysis on the grounds that empirical work (presumably: the "vignette" method favoured by the new "experimental philosophy" movement) is required to uncover *real* folk concepts. But this doesn't do justice to the normative element of analysis. They write:
Smith can reply that responses like those Nichols reports would not be part of the maximally consistent set of platitudes that people would endorse after due reflection. But this too is an empirical claim... (p.125)
How is this an empirical claim? What people would conclude on ideal reflection depends on what propositions are maximally coherent, etc. There's no experiment we can do to pin down what this is; any amount of actual reflection by third parties can always be rebuffed as insufficient to reach the ideal end-point -- "those participants," one may claim, "have not undergone *due* reflection." Maybe they've reasoned badly. The only way we can judge this is to engage in normative reasoning ourselves, and see whether the participants' answers correspond to what we've already determined to be true from the armchair!
Similar issues arise for the problem of persistent moral disagreement. The authors write:
the argument from disagreement cannot be evaluated by a priori philosophical means alone; what's needed, as Loeb observes, is 'a great deal of further empirical research into the circumstances and beliefs of various cultures'.
But I can't see how that would help, if in the end we can only judge others' rationality according to the substantive conclusions that they reach.
Besides, we should (in principle if not in practice) be able to tell from the armchair whether one position or another is rationally necessitated. Simply imagine all the conceivable cultural disagreements, and the difficulty of adjudicating between them. (Which ones obtain in the actual world seems quite irrelevant.) If we ultimately find a conclusion to be rationally necessitated after all, and others disagree (without providing any new reasons, since - ex hypothesi - we've already considered them all in reaching our previous conclusion), then that simply shows that they haven't engaged in fully ideal reasoning yet.
Matters are different in practice, of course, due to our own fallibility. Arguably, our credence in philosophical claims should be informed by the empirical (meta-)evidence provided by others' judgments of the issue. But can we ever hope to scientifically measure the rationality of their judgments, on purely procedural grounds (i.e. without begging the substantive question at hand)? If not, we may find that the real adjudicating work must still be done from the armchair.
Saturday, August 18, 2007
Scientism
Many otherwise-intelligent people have an unfortunate tendency to dismiss entire realms of inquiry out of hand. Perhaps the most common example of this is the failure to appreciate the possibility of a priori or non-scientific rational inquiry, i.e. philosophy. The prevalence of ignorant scientism in this thread (bashing Nick Bostrom's simulation argument) is remarkable -- though sadly not atypical.
One commenter suggests that an untestable hypothesis must consequently be classified as either 'myth' or 'garbage'. (He did not tell us how to test this very suggestion. I can only assume he was storytelling.) Another calls Bostrom's argument "pseudoscience gibberish". Yet another chimes in:
This is very much like saying the earth might really be only 3000 years old and $DEVIL just made it seem like its much older to fool everyone.
IOW, it is all hocus pocus claptrap what ifs and doesn’t belong in any science discussion.
The blogger (Peter Woit) himself writes:
I don’t see what the problem is with “lumping Bostrom’s ideas in with religion”. They’re not science and have similar characteristics: grandiose speculation about the nature of the universe which some people enjoy discussing for one reason or another, but that is inherently untestable, and completely divorced from the actual very interesting things that we have learned about the universe through the scientific method.
Really, if people can't tell the difference between a reasoned philosophical argument and random "hocus pocus" or religious proposals... well, let's just say it's further evidence of the urgent need for philosophical education in schools!
If you think that Bostrom's argument is flawed, then by all means put on your philosopher's hat and expose its errors. But this requires actually engaging with the argument. To dismiss it just because it didn't involve any labwork is the worst kind of scientism.
I should add a disclaimer. Sometimes people attack "scientism" when their real target is epistemic standards in general. (See the comments here, for example.) Not me. I'm all in favour of having rationally justified beliefs. What I'm attacking here is the lazy assumption that science is the only source of rational justification. This assumption is simply false (and indeed self-defeating). This should be too obvious for words, but apparently it needs to be said: rigorous philosophical argumentation can also provide rational support for a conclusion.
Hat-tip: Robin Hanson (who offers some incisive criticism of his own).
See also: Explaining Beliefs. (It's the same core issue, really: dogmatic dismissal is no replacement for reasoned inquiry. You can't tell whether a question is answerable until you try.)
Saturday, June 30, 2007
Why do you think you're conscious?
If consciousness is epiphenomenal, then it plays no part in the actual causal explanation of why we believe ourselves to be conscious beings. That seems problematic, or so Peli Grietzer argues in an interesting email [quoted with permission]:
There's one aspect of the Zombie argument that I always felt was a tough bullet to bite, though, and I wonder if you have any thoughts: While various non-causal accounts of knowledge can handle the core-analytic kind of epistemological issues about phenomenal beliefs that arise from epiphenomenalism, I often fear that it leaves us with no decent scientific hypotheses as to the evolution of phenomenal beliefs, other than the amazing luck of humans evolving to believe they are not zombies coinciding with humans really not being zombies.
The obvious counter-argument is that it's no different than the "lucky coincidence" we assume when we reject brain-in-a-vat type sceptical scenarios despite lacking any good probabilistic reasons to do so, but there's a possibly critical difference. At least if our beliefs about the external world are true there is a natural story about how we came to have such beliefs and that story involves the external world, while if epiphenomenalism is true we still have no natural story about how we came to have beliefs about phenomenal consciousness, that [the story] involves phenomenal consciousness.
The technical version of the Zombie argument doesn't commit to epiphenomenalism in the same way the more vivid "zombie world" way of telling it does, though, so maybe it's more of a problem for epiphenomenalism than for the zombie argument.
Chalmers offers a neat answer: "The content of a conscious being's direct phenomenal beliefs is partly constituted by underlying phenomenal qualities. A zombie lacks those qualities, so it cannot have a phenomenal belief with the same content." For example, my concept of phenomenal 'redness' is grounded in the phenomenal quality of redness that I experience. My Zombie twin talks about 'redness', but in actual fact his concept is empty, ungrounded. So he doesn't mean what I do by the term.
On this account, phenomenal qualities (consciousness) can influence what we believe after all. Not causally, of course, but more directly, through constitution. The physical facts alone do not suffice to fix the intentional facts (i.e. what our thoughts are about). Phenomenal properties are part of what it is to have a phenomenal belief -- a belief that's truly "about" those very qualities. So, although a zombie would make all the same noises, their words and cognitive processes (arguably not really "thoughts") wouldn't have the meaning that ours do.
So much for particular phenomenal beliefs like 'this is red'. The original challenge was to explain our general self-attributions of consciousness. Can "phenomenal properties and the capacity to have them [still] play a crucial role in constituting its content", as Chalmers suggests? Seems plausible enough; there's nothing in the zombie's mind for his alleged concept of 'consciousness' to latch on to, for example. Surely it must be empty, again. The upshot: if we weren't conscious, we wouldn't believe it after all. Sure, we would still utter things like "of course I'm conscious!" -- but they would just be so much meaningless babble.
So, zombies are incapable of any positive conception of consciousness (and thus derivative concepts such as zombiehood). But I can think of a residual problem: what of the even more general claim that physicalism is false (i.e. a minimal physical duplicate of our world is not a full duplicate of our world)? This claim involves no phenomenal concepts, and so presumably can be thought without any need for phenomenal properties -- they aren't constitutive of this belief, at least. But that leaves us with only physical factors to explain why we disbelieve in physicalism! Odd, no?
The only way out that I can see is for the epiphenomenalist to adopt the strong position that consciousness grounds all genuine intentionality, so that zombies can't have any real concepts, beliefs, or mean anything at all. This way, even our non-phenomenal beliefs (e.g. about whether physicalism is true) are partly constituted by -- or otherwise depend upon -- phenomenal properties.
[Correction: an alternative option has been pointed out to me: the belief against physicalism inherits its epistemic warrant from the phenomenal beliefs from which it is inferred. In case of zombies, there is no such warrant to be transmitted.]
Consciousness explains why we have the beliefs we do, because without it, we wouldn't have any genuine beliefs at all.
Friday, June 22, 2007
Coherent Persuasion
Peter argues that no-one has "ever been convinced to change their mind by a rational argument". I'm not convinced.No rational argument then can be constructed to ever change a person’s mind, because we can never get to premises that people must accept.
Even if we grant this premise (must we?), the conclusion simply doesn't follow. At most, it shows that arguments won't necessarily rationally convince everyone. It remains an open possibility that some people will indeed be rationally convinced, since they may well be more committed to the truth of the premises than to the conclusion's falsity.
Still, I think there is something artificial about an argument's directionality, as demonstrated by the adage that "one man's modus ponens is another's modus tollens." Valid arguments are easily inverted, simply by switching the conclusion with a premise and negating each. Validity is preserved; the contraposed argument is logically equivalent to the original. (This refutes the common claim that logic tells us how to reason. At most, logic can provide us with wide-scope norms against inconsistency, but it cannot tell us which of the conflicting claims to give up.)
So, philosophical debate should be thought of as producing... not "arguments" per se, but logical maps -- "inconsistent triads" and the like -- to show which claims cohere best with certain others, which ones rise and fall together, etc.
It should be quite clear that this process can be rationally persuasive. We feel rational/psychological pressure to have a coherent belief set. So if someone can show that some claim P coheres better with our other beliefs than does our present belief of not-P, this may bring us to change our minds about P. And, indeed, this happens all the time.
People often hold opinions due to conceptual misunderstandings. (Think of the popular false dilemma between relativism and dogmatism.) These are easily cleared up, and any half-rational agent will change their mind upon learning of their error. Much if not most philosophy is simply a matter of overcoming sloppy thinking -- appreciating possibilities or implications that we'd previously missed.
Peter is implicitly assuming that we already have maximally coherent belief sets, so that no argument (logical map) would have any new information to give us cause to update our beliefs. But this assumption is patently false. We can - and do - learn things from others' arguments, and change our minds accordingly.
P.S. I've previously, in response to a reader's challenge, given examples of changing my mind in response to rational arguments. The issue of normativity and ultimate ends is the big one. More recently, learning about 2-D semantics radically changed my opinion of conceivability arguments. So, those are two very fundamental changes right there. (Of course, it's open to Peter to insist that the changes had non-rational causes. But that would seem unmotivated and uncharitable. I certainly think that my views have improved with time, and didn't merely "shift" in a rationally neutral fashion.)
Question for regular readers: have any arguments on this blog ever led you to revise your beliefs?
Monday, May 21, 2007
Radical Skepticism vs. Anything Goes
Surely this post's title is a false dilemma. Nevertheless, it seems to be a popular defense of religious belief, to say that "atheism is a faith position too", e.g. because we need to assume that our senses are a reliable guide to reality [HT: OB], or because objective morality is no less "mysterious" than God, etc. This strikes me as not so much an argument as a negotiation: "Your beliefs are unjustified too, so I won't say anything if you don't!" Let's all just lower our epistemic standards and be one big irrational family.
Or let's not.
Not all axioms are created equal. Some assumptions are more reasonable than others. Given our commitment to making sense of the world as best we can, we are rationally obliged to believe in the preconditions of our success, i.e. that our basic methods of inquiry (science and reason) are on the right track. This is an entirely reasonable assumption to make, and in no way does it legitimize making further - arbitrary - assumptions in addition.
This becomes even clearer if we reject the foundationalist model of justification in favour of coherentism. One's maximally coherent belief-set would contain the claim that one's senses are generally reliable. It would not (atheists argue) contain the claims made by pop theism. They just don't fit together so well with everything else we (take ourselves to) know about the world.
If it's really the case that we have no good reason to believe something, then we shouldn't believe it. So it would be irresponsible to accept the theist's cease-fire; their reasoned criticisms should instead be welcomed! But, I would argue, we actually do have good reasons to believe in those other things (e.g. morality, the external world) in the alleged analogy. On the other hand, we don't have such good reasons to believe in pop theism. So, I think we should simply reject the analogies.
Granted, even atheists must make some assumptions. But, again, some assumptions are more reasonable than others. It's not always obvious what we should (most reasonably) believe. It's not always easy to avoid falling off into either extreme of complacent skepticism or complacent relativism. But of course this challenge calls for more, rather than less, critical epistemic discernment. Don't throw up your hands -- think!
Tuesday, May 15, 2007
Coherence and Comprehension
Responding to my post on verificationism and base facts, Jim Ryan writes:
I wonder whether Richard's view entails that one can understand an incoherent term (such as "square with only three sides"). After all, "I know what it means, I understand it, but I just don't see how it could be rendered coherent" sounds Richardesque. I suppose he might say that the incoherence precludes comprehension. But that seems arbitrary. Why won't he also allow that evidential vacuity precludes comprehension, as well? Again I say that the mind is large and its imagination powerful. It can imagine a logically impossible thing (especially if it's in a sort of dreamy state: try it, you can do it. Or if the contradiction is buried deep enough, you can accomplish the task in a clear-headed state.) It can mistake this for comprehension. It can imagine the correct application of an evidentially vacuous term (e.g., "zombie") and mistake this for comprehension, too. How can Richard distinguish these two, such that in the latter case there is in fact no mistake?
Granted, our claims to understanding are fallible -- one can't be certain that further reflection won't reveal some hidden incoherence in a notion. There's a gap between prima facie conceivability and ideal conceivability. A nice example of this is the Grim Reaper paradox:
There are countably many grim reapers, one for every positive integer. Grim reaper 1 is disposed to kill you with a scythe at 1pm, if and only if you are still alive then (otherwise his scythe remains immobile throughout), taking 30 minutes about it. Grim reaper 2 is disposed to kill you with a scythe at 12:30 pm, if and only if you are still alive then, taking 15 minutes about it. Grim reaper 3 is disposed to kill you with a scythe at 12:15 pm, and so on. You are still alive just before 12pm, you can only die through the motion of a grim reaper's scythe, and once dead you stay dead. On the face of it, this situation seems conceivable — each reaper seems conceivable individually and intrinsically, and it seems reasonable to combine distinct individuals with distinct intrinsic properties into one situation. But a little reflection reveals that the situation as described is contradictory. I cannot survive to any moment past 12pm (a grim reaper would get me first), but I cannot be killed (for grim reaper n to kill me, I must have survived grim reaper n+1, which is impossible). So the description D of the situation is prima facie positively conceivable but not ideally positively conceivable.
How should we interpret this? I guess I am a bit tempted by the line Jim attributes to me: "I can understand the set-up, I know what it means, and I see that it's incoherent!" But this trades on an equivocation. I can understand each of the descriptive components in isolation, but that's all. It remains a total mystery how they fit together -- what is supposed to happen after the strike of 12? It can't be understood. It's incoherent. But I repeat myself.
It's not arbitrary to say that "incoherence precludes comprehension." On the contrary, it's analytic! Coherence just is comprehensibility. To call something "incoherent" is precisely to say that it cannot be comprehended by any rational mind whatsoever. (Of course, something coherent but complicated might be "incomprehensible to me" in the limited sense that, due to my contingent cognitive limitations, I simply happen to not understand it. But that's not the relevant sense of the term here.)
On the other hand, I just don't see any reason to think that evidential vacuity precludes comprehension. And I do see reasons -- in the form of apparently coherent counterexamples (zombies, multiverses, etc.) -- to reject such a stringent requirement.
Jim concludes:
Richard needs to say what is the difference between "comprehensible" and "suspiciously incomprehensible" other than a feeling of "I've got it!" I don't trust that feeling. I need epistemic, evidential terms.
That seems fair enough, given how fallible such intuitions are. The difference between true and false intuitions is a matter of fact that won't always be transparent to us, namely: would further reflection lead me to change my mind?
Monday, April 23, 2007
Does Philosophy Need Science?
I reckon not. (Well, perhaps in practice, e.g. as an imaginative aid, but not in principle.) Whenever you're tempted to appeal to empirical data, simply conditionalize it out and you can safely carry on philosophizing in the a priori realm of possibilities.
Of course, we may be most interested in actual-world problems, e.g. interpreting modern physics, addressing salient ethical and political issues, etc. But there doesn't seem any reason why they couldn't in principle be addressed just as well from an empirically neutral position which entertained our actual situation as a merely hypothetical scenario. Indeed, given sufficient imaginative and rational powers, the armchair philosopher (or even the disembodied, floating-in-the-void philosopher) should be capable of achieving a kind of "limited omniscience", knowing everything there is to know about the various possibilities (except for which one happens to be actual -- but never mind that one little fact).
It might be objected that science brings to light new possibilities that would otherwise seem inconceivable -- e.g. space-time relativity. But this is merely to note that experience is a useful imaginative aid; it plays no necessary role in the actual justification of our philosophical beliefs. Einstein's theory is enough; it need not be borne out by the empirical data. His conceptual scheme alone is enough to show how space and time could turn out not to be absolute. (Unless there's really a hidden contradiction in there, in which case ideal rational reflection should suffice to expose the impossibility.)
Am I wrong? (And do you have to conduct an experiment before you can tell?)P.S. Thanks to Jack for getting me thinking about this topic.
Friday, April 20, 2007
Brainwashing
Jeremy Stangroom (Talking Philosophy) discusses some difficulties in analyzing our concept of brainwashing. Some would consider religious schooling to be a (perhaps mild) form of brainwashing, for instance, drawing on an understanding of brainwashing as dogmatic instruction. To this, Jeremy raises the History Teacher Objection:My teacher was an old style facts and dates kind of guy. He taught by writing notes onto a blackboard. We copied them down. There was no questioning, no dissent. Nothing to suggest that the details of history were contested, etc. But presumably people would not want to claim that I was being anything like brainwashed by my history teacher…
My suggestion: legitimate instruction exhibits epistemic sensitivity, or - more loosely - is responsive to reasons and evidence. If the facts and dates of history had been different, then so would the History Teacher's instruction have been. His teaching, though itself apparently 'dogmatic', is embedded in a broader academic system (of textbook writers, etc.) that is broadly reliable and responsive to evidence.
The same is not true, we may suppose, of most religious instructors. Even if Plantinga or other philosophers of religion established the truth of theism, they are too disconnected from most religious instructors to protect the latter against charges of brainwashing. The Sunday School teacher would teach much the same things no matter what the best philosophers discovered. Even if their teachings by some fluke happened to be true, it still fails to be the case that they are teaching it because it is true.
Just as a true belief may fail to constitute knowledge due to the holding and the truth of the belief not being related in the right way, so too a true or justified proposition may fail to be taught legitimately -- and instead constitute brainwashing -- because the act of teaching it fails to be properly responsive to these normative qualities of what's being taught.
Update: Could we be more explicit here, and say that legitimate instruction is precisely that form of teaching which is apt to produce knowledge? We can then pass the buck on the tough epistemological questions, whilst plainly distinguishing the history teacher from the sunday school instructor. However the details may go, those suspicious of religious brainwashing presumably hold that the religious instructor is not apt to produce knowledge in her students (even if her teachings happen to be true).
Friday, January 26, 2007
What is a "valid" belief?
Okay, while I'm expanding my vocabulary, any idea what a "valid" belief is?
For example, D.A.N. writes that standing up for your beliefs involves "understanding that other belief systems are valid, and no less valid than your belief system." We are also meant to understand that "beliefs do not always have [need?] concrete evidence to support them and that a lack of evidence does not necessarily make a belief system invalid."
Now what in the world does he mean? I would have thought that "valid" meant something like "good", "reasonable", or "justified" (i.e. epistemically permissible). But then D.A.N.'s claims would be plainly false. It's just not true that all belief systems are equally well grounded. You really shouldn't hold baseless beliefs. And it wouldn't make much sense to "stand up for your beliefs" if you didn't think they were objectively any better than the alternatives. Emotivists aside, opposing torture isn't like cheering for your local sports team.
In short: relativism is false. But are those who claim that 'all beliefs are equally valid' just silly relativists, claiming that all beliefs are equally good? A more charitable interpretation, I guess, would be to understand 'valid' in this context as meaning something more like 'tolerable'. All belief systems are equally tolerable. Some are stupid, perhaps, but that's no excuse for persecution.
But now we seem left with a truism. (Who seriously advocates a new Inquisition to forcibly root out false beliefs? Setting aside socially pernicious ones, at least...) There's not much point asserting something that no-one disagrees with anyway.
Perhaps it's simply a metaphorical call to refrain from expressing negative judgments. Some beliefs may be daft, but you shouldn't say so. It ain't nice. For that matter, you probably shouldn't even suggest that some beliefs are false. Believers might be offended. Now, it really wouldn't do to imply that people are ever less than perfect -- they might not like that, see. What? Something to be said for recognizing room for improvement? No, no, that clearly implies that we're not already perfect. That just won't do at all. Not at all. No.
*cough* Sorry, just had to get that out of my system.
To be fair, overly harsh scorn and derision might take the fun out of life. But if we value truth and rationality at all, there must be some legitimate place for reasoned criticism in the public sphere. If weaselly talk of "validity" is used to undermine these values, that's something to watch out for.
Friday, January 05, 2007
Constructivism and Intuitions
A major issue in philosophical methodology concerns the use of "intuitions" -- perhaps as foundational premises, or else the initial data points which our theories then aim to systematize. The difficulty, as Alex recently pointed out, is that we don't have any obvious reason to think that such intuitions are in tune with the facts. Philosophers occasionally speak of a faculty of "rational intuition", which is supposed to somehow detect ("intuit") moral, mathematical, or other abstract truths of the Platonic realm. But it all sounds a bit wacky. (How is this mysterious faculty supposed to work, exactly?)
But perhaps the problem is not so bad if we reject Platonism. I tend to think that philosophical (as opposed to material) facts are not really things that exist out in the world. Though objective enough, their ontological status is better seen as that of a rational construction. According to this view -- call it "Conceptualism" [Update: "Constructivism" seems a better label] -- philosophical truth "just is the ideal limit of a priori inquiry; it does not answer to the sort of independent reality that might sensibly be considered beyond all epistemic reach." Whereas physical facts are made true by existing things in the world, philosophical facts are made true simply by the fact that they are what ideally rational agents would believe. For example: the truthmaker for "the cat sat on the mat" is a particular physical event involving a cat and a mat in the appropriate arrangement. The truthmaker for "2+2=4" is that ideal rational reflection would lead one to endorse the belief.
So what does all this mean for the reliability of our intuitions? Well, if they no longer have to answer to an independently existing realm of facts, perhaps they're not in such bad condition as we thought. Note that I'm not denying that there is an objective truth of the matter for many philosophical questions, so that our intuitions may in fact lead us astray (if ideal rational reflection would cause us to revise them, for example). Our intuitions must answer to this rational construction; the point is that the construction may not be wholly independent of them in the first place.
In short: the views we hold now, which are prima facie coherent and plausible, are reasonable - if fallible - guides to what we would find coherent and plausible on ideal rational reflection (which, for philosophical questions, is simply to say what is true). Intuitions have justificatory force because they're already on the road to constituting truths. Sure, obstacles might arise on further reflection that prevent the initial beliefs from being true after all. But otherwise, they're home free.
Saturday, October 14, 2006
The Ubiquity of Apriority
Some philosophers are skeptical of whether there can be a priori (non-empirical) justification. But I'm not sure how they can avoid it. For any instance of empirical justification, it seems like we can construct a parallel instance of a priori justification simply through conditionalization. Suppose that empirical evidence E would justify your drawing conclusion C. Then presumably you could justifiably believe the conditional "if E then C" prior to experiencing E. We can repeat this procedure to conditionalize out all empirical grounds for belief, and the result will be a conditional statement that is justifiable a priori.
Bonjour suggests something similar in In Defense of Pure Reason, p.5:Could an argument of any sort be entirely justified on empirical grounds? It seems clear on reflection that the answer to this question is "no." Any purely empirical ingredient can, after all, always be formulated as an additional empirical premise. When all such premises have been explicitly formulated, either the intended conclusion will be explicitly included among them or it will not. In the former case, no argument or inference is necessary, while in the latter case, the needed inference clearly goes beyond what can be derived entirely from experience. Thus we see that the repudiation of all a priori justification is apparently tantamount to the repudiation of argument or reasoning generally, thus amounting in effect to intellectual suicide.
What response can the radical empiricist make to this?
Thursday, September 28, 2006
Confusing the Cogito
Timothy once suggested that I should write a series of posts clearing up "common philosophical misconceptions". An obvious place to start, as he notes, is with the most famous line in philosophy, Descartes' cogito: "I think, therefore I am."
The popular misunderstanding is evident in the following joke:Descartes is sitting in a bar, having a drink. The bartender asks him if he would like another. "I think not," he says, and vanishes.
The current Wikipedia article dismisses this move as sheer logical fallacy (denying the antecedent), but I think there is something deeper going on. We see this when people joke, "I drink, therefore I am", intending their comment to reveal something about their person (e.g. that social drinking is central to their lives, or something they highly value). This indicates that they were interpreting Descartes as claiming that thinking is, in some sense, the reason why he exists. After all, that does sound like something a philosopher might say -- compare Socrates' claim that "the unexamined life is not worth living."
People commonly imbue conditionals and inferences with metaphysical significance. For example, the claim "if it is raining then the grass is wet" naturally suggests a causal relation between the two: it's raining, and that's why the grass is wet. Similarly, one might interpret "I think, therefore I am," as meaning something like, "I think, and that's why I am." This interpretation explains why people are tempted by the converse inference from non-thinking to non-existence. It's not so illogical after all.
But it is a mistake all the same. Descartes isn't claiming here that thought is the reason for his existence. Rather, it's simply an infallible indication of it. An evil demon might deceive you about all manner of ordinary facts, but from the mere fact that you're thinking or having mental experiences at all, it logically follows that you must first exist. You couldn't possibly be mistaken about that, at least, no matter what the demon might try.
Note the crucial distinction between epistemology and metaphysics. Epistemology is about evidence and what we can know. Metaphysics is about reality in itself. The two can easily come apart, as when we imagine a hypothetical scenario involving deception: we imagine that something is true in fact, though nobody knows it because the evidence is misleading. We can similarly imagine someone being psychologically certain that they "know" something, when in fact their belief is not true at all.
Now, the Cogito highlights the logical relation between "I am thinking", and "I exist". If the first is true, this logically guarantees that the second must also be true. This has epistemic significance. But it is not metaphysically loaded. The abstract logical relation says nothing about how the two facts are connected in the structure of reality. In particular, it is not to claim any metaphysical dependence of the second on the first, i.e. that I exist only because I'm thinking, such that if my thinking were to cease then so would my existence.
(N.B. A Cartesian [from Descartes] Dualist will actually agree with the metaphysical thesis that we are essentially mental beings. But this is based on other arguments, not the cogito.)
Disclaimer: I'm no historian, so bear in mind that my purpose here is to clarify the logic of the cogito and related concepts, not to faithfully represent the historical Descartes. Take any claims about the latter with a grain of salt.
Friday, September 22, 2006
Why Believe in the Past?
The universe could have come into existence just now, false memories and all. What basis do we have for ruling out this possibility, or even thinking it unlikely? It's a bit ad hoc, I guess. It seems that positing a real history provides us with a better explanation for why things are as they are now. But this apparent benefit may be illusory. After all, we have no further explanation of why the universe ever began at all. Many atheists simply take it as a brute fact. But if we are tolerant of such bruteness, then why wait? It seems arbitrary. Worse, it's less parsimonious than doing away with the past altogether would be.
In short: if you're willing to posit the existence of the entire (4-d) universe as a brute inexplicable fact, why bother with the past at all? Why not cut to the chase and simply posit the brute existence of the present timeslice (and nothing else)?
Saturday, August 19, 2006
The Most Radical Skepticism
Might someone feel as though they have a rational grasp on a logical certainty, when they are in fact mistaken? If so, should that undermine our own confidence in logic?
(These look like annoying questions, with a whiff of undergrad "anything goes" sophistry about them. But perhaps they're worth taking seriously, at least for the duration of one blog post.)
This is rather different from your run-of-the-mill BIV-based skepticism. There it is suggested that our actual experiences could be misleading. It is not so clear that our actual reasoning could be mistaken. If modus ponens is a valid rule of inference, then presumably it couldn't fail to be so. Still, as recently noted, there's something a bit unsatisfying about such conditionals, if we're not in a position to assure ourselves of the antecedent.
In any case, the initial difference can be overcome with a little abstraction, as in my introductory questions. Rather than asking about the particular things (de re) that we consider self-evidently necessary, we may raise the general (de dicto) question of whether we could find falsehoods to be "self-evident". And if that is a genuine possibility, we should want to find some way to determine that such a scenario is not our actual condition. Lacking such findings, logical skepticism might get off the ground in much the same way that empirical skepticism does.
Worse, logical skepticism might render itself immune to any form of refutation. That is, even if you were to find (what appears to be) a water-tight proof against it, the Most Radical Skeptic could simply iterate her challenge, applying it now to the proof itself. ("Might you not find just as convincing a proof that was actually mistaken? Your certainty is a response to the apparent soundness of the proof. Whether it is actually sound or not is a separate question. We cannot get beyond appearances; your feeble attempts are futile since they merely appeal to further appearances, and so fail to bring us any closer to the impossible goal of directly grasping the raw truth.")
We might try to respond by denying the assumption of phenomenological identity posited in the initial premise. Compare my old post on dream skepticism, and especially the idea that an unnoticed absence is not the same thing as phenomenal presence. Perhaps there is something distinctive about the feeling of genuine rational apprehension, such that you can know when you have it, even though you often won't know when you lack it. (Just like you can know when you're awake, even though you often don't know when you're asleep.) Then -- as briefly discussed in the linked post -- an analogue of my response to dream skepticism might also apply here. We can be confident in the epistemic necessity of Descartes' cogito, even though a drugged logician might be equally confident of some wacky falsehood. The difference is that his confidence would be based on muddle-headedness, whereas ours is based on rational clarity. And even though the muddled one is in no position to tell the two experiences apart, the clear-thinker surely can.
Or maybe not? Are we in a position to be sure that our thoughts are clear and rational? Can we be sure that we're not suffering from logical delusions? I'm not too sure what to say about this. Feel free to drop your opinion into the comments box!
If all else fails, I guess we can always fall back on the old transcendent-practical argument that we've nothing to lose and everything to gain by trusting logical appearances at least to some degree. Most Radical Skepticism leads to total paralysis: the Most Radical Skeptic answers absolutely every question with a hapless shrug. They're hopeless! But the rest of us seem to be doing okay, by comparison.
Of course, I can't say that's a knock-down argument for assuming that logical appearances are reliable. The most annoying skeptic would never grant it (simply because they'd never grant anything). I guess I can merely offer it as friendly advice, and let them make of it what they will...
The Anthropic Principle
Dom Eggert writes:
[T]he likelihood that life will arise in this universe does not change even if there are millions of non-life-supporting universes "out there" (assuming that universes are closed systems that don't interfere with each other). If this reasoning is correct then, from our perspective, it is no more rational to believe that there are infinitely many universes than to believe there is just one--it's merely an aesthetic preference.
This strikes me as mistaken. It's true that the existence of other universes doesn't affect the probability of this universe - "u42" let's say - being capable of supporting life. But that isn't what needs explaining. We merely need to show how there could be some universe or other that supports life. The locative fact that it's ours in particular can be got for free, by appeal to the Anthropic Principle.
Compare: "Of all the planets in the universe, how is it that we ended up on one of the few capable of supporting life? Isn't this monumentally unlikely?" This sounds like a silly question. It's not as if we might instead have been asking the question from the blistered surface of Mercury. Living - and hence being somewhere capable of supporting life - is a precondition for even asking the question. Finding ourselves alive on a lifeless planet is not a possibility that ever needed to be ruled out.
A more troubling question would be: "How is it that there are any life-supporting planets at all?" For clearly the total absence of life is a coherent alternative, so we need some explanation of why that didn't come to be. (Otherwise we must appeal to brute chance or coincidence, but that isn't much of an explanation!) And here the appeal to multiple universes might help. If there are zillions of universes, the chance that life exists somewhere or other suddenly looks a lot more likely.
Note that once it has been explained how life could plausibly exist somewhere, it's no great mystery how come it exists in our universe in particular. Maybe it's unlikely that u42 would contain life, but we don't really care about u42. For explanatory purposes, we care about "the universe we're in", de dicto not de re. And the probability that whatever universe we're in contains life is pretty well certain.
Again, the Anthropic Principle by itself cannot solve the whole problem. It cannot address the question of why we (or life-supporting universes) exist at all. For that we need the multiverse hypothesis. The Anthropic Principle can only help with the locative question: presupposing that there are life-supporting locations, why do we find ourselves in one of them rather than somewhere else? Combine the two and we get a relatively satisfying explanation, I guess. (More so than any alternative I've yet come across, anyway.)
So, contra Dom, I think we could rationally believe the multiverse hypothesis, as an inference to the best explanation. We simply need to be clear on what it serves to explain. It does not explain why u42 supports life. That's not something I feel any need to explain. Rather, what the multiverse hypothesis initially explains is how any actual universe could support life. Conjoined with the anthropic principle, it can then explain why we find ourselves in a life-supporting universe.
(See also: Why does the universe exist?)
