Sunday, April 25, 2010

Huemer's Self-Defeat Argument

Michael Huemer forcefully advocates Phenomenal Conservatism (PC), the view that intuitive 'seemings' are prima facie justified. That is: "If it seems to S that P, then, in the absence of defeaters, S thereby has at least some justification for believing that P." (We should further add that, for Huemer, any possible defeaters must themselves be grounded in appearances.) He takes the following "self defeat argument" [quoted from our seminar handout] to rule out all competing views:
1. (Almost) all beliefs are based on appearances. (Exceptions: faith, self-deception.)
2. A belief is justified only if it is based on something that is a source of justification.
3. Therefore, there are justified beliefs only if appearances are sometimes a source of justification. (From 1, 2.) (Faith and self-deception are obviously not sources of justification.)
4. If PC is false, then appearances are never a source of justification.
5. So if PC is false, then no belief is justified. (From 3, 4.)
6. So no one is justified in believing any alternative theory to PC. (From 5.)

I'm not sure that (6) follows from (5). Some philosophers who either haven't seen or aren't convinced by Huemer's argument may find that some alternative theory X seems right to them, and if PC is true then this undefeated appearance can justify their belief in X. But never mind that: the conclusion in (5) is strong enough to establish PC (just tollens on the further premise that some beliefs are justified).

A more serious flaw, I think, is premise 4. I think the most plausible alternative to PC allows that appearances are sometimes a source of justification. It just adds a further objective constraint: the content of the seeming must not be objectively crazy. This alternative view yields more plausible results than PC when we consider severely incompetent agents. PC seems to imply that any proposition whatsoever can be justifiably believed: it merely requires that the proposition seem true to the agent, and that they not have any other relevant seemings (which could potentially serve as defeaters on Huemer's view). But severely logically confused agents (for example) should not qualify as having justified logical beliefs. If it seems to you that 2 + 2 = 4, and it seems to me that 2 + 2 = 99, these two beliefs are not equally rational or justified -- even if we both have equally strong-seeming intuitions. In this case, your mind is functioning properly and mine isn't: my belief is just crazy, even if it doesn't seem so to me from the inside. As I keep saying, one can be irrational without realizing it.

So, this strikes me as an appealing alternative to Huemer's view which isn't undermined by his self-defeat argument. Intuitions justify, except when they're objectively crazy. We may add that the previous sentence is not itself on the list of 'objectively crazy' claims. Hence, if this view is true, then those who find it intuitively plausible can justifiably believe it. It isn't self-defeating. (One may be suspicious of the notion of 'objective craziness', and so reject the view on those grounds. But that's a different objection.)

[Disclaimer: As always, I'm not making any claim to originality or uniqueness here -- several others in our seminar seemed to be thinking along similar lines.]


  1. Hey Richard,

    I think there are lots of problems with this argument.

    Suppose I say that you shouldn't trust the word of a gambler and I believe p on the word of a gambler. That's not self-defeating, not unless I believe/acknowledge that my belief is based on the word of a gambler. It's not enough that this is my basis, as a matter of fact.

    So, suppose I have the following view: my beliefs are based on facts that are made evident to me by experience, intuition, memory, etc... Suppose the view is false, but I don't know it. I might believe that beliefs based on appearances and nothing else aren't justified. It might be that my beliefs are based on appearances and nothing else. But, as I deny that this is so, it's not self-defeating to deny that seemings/appearances justify.

    There's another serious problem with the argument. If it PC is an internalist view (which it is for Huemer), it says nothing to the externalist who says that justifying reasons are internal states but justifying reasons only actually/successfully justify if additional external conditions aren't met. So, on the view of perceptual justification I like, believing p with justification when it perceptually appears that p requires that it seems to you that p because of your experience _and_ your experience doesn't misrepresent how things are. I can say that the justifying reason is what he says it is, but we know that the presence of a justifying reason for believing p doesn't entail that the belief is justified because there can be additional defeaters. Now, maybe defeaters have to be accessible, but _that_ is something that you have to argue for independently. So, if PC is supposed to be a kind of internalism, you need a lot more than the self-defeat argument for PC.

  2. Hi Clayton, that sounds right. Something (structurally) like your last paragraph was what I was trying to get at in my suggestion that we may simply add "a further objective constraint" on when intuitions successfully justify. Objective craziness (or, on your version, "mispresent[ing] how things are") can be understood as a defeater without any risk of self-defeat.

  3. Hi Richard,

    Aren't you denying more than you need to? You can get all you want without thinking that the fact that the proposition believed is crazy is a defeater. Instead, you could just think that the fact (when it is a fact) that the proposition isn't crazy is just a background condition for an appearance of that proposition being an appearance that can justify. If you said that, you could agree with Huemer that only appearances justify and only appearances defeat. You've just added an extra background condition on what it takes for an appearance to be able to justify.

    For what it's worth, I think that this is what Clayton should say, too (I suspect he might). The fact that the perception gets things right is just a background condition that must be met in order for the content of the experience to be a justifier (I take it Clayton thinks that the contents of the experiences are the justifiers). But that's a different claim than saying that the fact that some experience gets things wrong is a defeater.

  4. Hmm, could you say a bit more about what that difference is? (I take it that the absence of defeaters is a background condition for justification. So for these to come apart, there must be some background conditions whose absences don't thereby count as defeaters. Maybe an example would help me grasp this distinction?)

  5. If I remember Huemer's paper correctly, I expect he'd respond in something like the following manner.

    Suppose we add in some constraint to PC--we say that only certain appearances justify. Take some case where you believe that P, and it seems to you that P, and P isn't crazy. In such a case, both PC, and the amended view that Richard and Clayton suggested will agree that you have propositional justification for P.

    Now, in order for your belief that P to be doxastically justified, it must be based on the fact in virtue of which it is propositionally justified (or something along these lines). But (big assumption here), your belief is based on the fact that it appears to you that P--not on the fact that it appears to you that P and P isn't crazy. Even if P were crazy, if it seemed to be true to you, then you'd believe it.

    So if the restricted version of PC is right, then even though we have propositional justification for various beliefs, our beliefs are never doxastically justified, since they're always based on the fact that it appears to us that P, not on the fact that it appears to us that P AND (insert restriction here).

    Like I said, I seem to remember him making an argument along these lines, though I worry that it requires very strong assumptions to work--it seems to require that whenever it appears to us that P (even if P is crazy), we'll believe that P. And I'm pretty sure Huemer doesn't think that (illusions like the Muller-Lyer, I'd think, are supposed to be cases where it appears to you that something is true, but you don't believe it).

  6. Richard,

    There are lots of background conditions whose absences don't count as defeaters. A background condition for my belief in p to be justified is that I believe p, but the fact that I don't believe p isn't a defeater of my belief that p. Here's an example only having to do with propositional justification (at least PJ on your view): A background condition for some proposition p having PJ is that it appears to me that p, but the fact that it's not the case that p appears to me is not a defeater of p.

    Daniel: I think that was Huemer's response when he thought that Richard thought that membership in the set of non-crazy propositions was directly playing a justificatory role. I think that Richard moved to the view that the fact that the proposition believed is crazy is a defeater in response to the argument you give.

    I think that we can see that this argument should fail by Huemer's own lights if we keep in mind that some of these things can be background conditions. For according to his own view, a background condition on some proposition having propositional justification is there aren't any defeaters. This fact is one of the facts in virtue of which some proposition is propositionally justified. But he surely doesn't hold that your belief must be partially caused by the fact that there aren't any defeaters in order to be doxastically justified. Similarly, people who want to add extra conditions can say that their extra conditions play the same type of background role as the fact that there are no defeaters plays for Huemer.

  7. Yeah, I moved to the 'defeater' version of the view for dialectical reasons. But I'm actually not convinced there's anything wrong with the original version. There seems a perfectly natural way to carve up the components of PJ into those that can causally ground belief (i.e. the appearance) and those that can't (i.e. the property of objective non-craziness). So on this kind of picture, it'd be natural to understand doxastically justified belief as simply belief that is based on the component(s) of PJ that can ground beliefs. An account of DJ along these lines would seem to do just as well on the standard cases of PJ without DJ, etc.

    Overall, I'm agnostic on which of the three versions of the view is the best way to go, largely because I don't have enough of a sense of what the differences amount to. (What exactly am I committing myself to if I call something a defeater rather than calling its absence either a background condition for justification, or a component of the justification? How does one standardly decide which of these three categories some epistemically relevant consideration belongs in? I have views about what's epistemically relevant. I don't think I have views about this more fine-grained stuff.)


Visitors: check my comments policy first.
Non-Blogger users: If the comment form isn't working for you, email me your comment and I can post it on your behalf. (If your comment is too long, first try breaking it into two parts.)