(JJ) If you are justified in believing that p, then p is warranted enough to justify you in phi-ing, for any phi. (Quoted from p. 99)
(Moderate Externalism about Justification) Justification does not supervene on the subject's internal states. In particular, external properties like reliability and Gettierizedness can make a difference in whether one is justified in a particular belief. (Paraphrased from p. 107)
Fantl and McGrath argue that (JJ) implies that 'purist fallibilism' about justification cannot be true. Now as I wrote a little while ago, I don't really buy into the notion of purism. And to be honest, I have some problems with the notion of fallibilism, too -- I'll try to write them up sometime soon. But set all that aside. The basic idea is that, if you accept (JJ), then you think that there might be two subjects that differ only in, for example, how important p is to each subject, such that one is justified in believing that p and the other is not. I guess I think that's right, although I'm thinking of things in a way different from the way Fantl and McGrath do.
Fantl and McGrath think that people who accept this and are also moderate externalists (hereafter 'externalists') "commit themselves to counterintuitive claims about action." First, Fantl and McGrath observe the familiar point that externalists think there could be intrinsic duplicates who differ in their justification facts; externalists, therefore they face the New Evil Demon problem. That's familiar stuff, and, as Fantl and McGrath say, there are many possible responses. But they think things get worse once you also accept (JJ). They write:
Moderate externalists who accept JJ not only have to say that two subjects who differ only in how reliable they are can differ in what they are justified in believing. They also have to say that the subjects can differ in what they are justified in doing. This is counterintuitive. (108)
It's not really clear to me that this is a counterintuitive verdict. But more to the point, I just don't see why Fantl and McGrath think externalists who accept JJ are thereby committed to it. They don't, as far as I can see, explain why they think this result should obtain. It plainly doesn't follow in any direct way from externalism and JJ; externalism says that external properties can influence belief-justification facts, and JJ gives one link between belief-justification and action-justification, but it's just nowhere near strong enough to imply, as Fantl and McGrath seem to think it implies, that external properties can shift action-justification facts.
Take subject LOW who is justified in believing p, and for whom p justifies Xing. Externalists are committed to the possibility, in at least some cases, of another subject, HIGH, intrinsically identical to LOW, who is not justified in believing p. Fantl and McGrath seem to think that externalists are committed by (JJ) to think it possible, consistent with these stipulations, that HIGH is not justified in Xing, but (JJ) just doesn't get them anywhere near that commitment. Indeed, (JJ) is silent about HIGH. This principle tells you about what happens when a subject is justified in believing p; it entails nothing about what happens when a subject is not justified in believing p. For all (JJ) says, p may justify HIGH in Xing, too. (Consider this coherent principle that entails (JJ): If anyone intrinsically identical to you is justified in believing p, then p is warranted enough to justify you in phi-ing, for any phi.)
Suppose we considered a stronger, biconditional, principle:
(JJ*) If and only if you are justified in believing that p, then p is warranted enough to justify you in phi-ing, for any phi.
I don't know whether (JJ*) is plausible or not; it's strictly stronger than the principle Fantl and McGrath defend. It gets around the problem I just raised for their charge against the externalist. But even (JJ*) isn't strong enough to deliver an entailment from externalism to a difference in what actions are justified between LOW and HIGH. Externalism and (JJ*) commit one to the verdict that p cannot justify HIGH in Xing, even though it can justify LOW in Xing. That's a far cry from the stated claim that nothing justifies HIGH in Xing. And I just don't see any plausible argument that this could be the case. It may be, for all (JJ*) says, that HIGH and LOW must be justified in performing all the same actions, but that they have divergent propositions justifying those same actions. (The plausible way to develop this line, I think, is that HIGH's reasons are a proper subset of LOW's.)
So I don't think that externalists who like (JJ), or even those who accept (JJ*), are committed to the allegedly counterintuitive claims about action that Fantl and McGrath charge.
I had an exchange with J&M (or F&M) over at Peasoup on issues related to this. In the book they say, "Moderate externalists who accept JJ not only have to say that two subjects who differ only in how reliable they are can differ in what they are justified in believing. They also have to say that the subjects can differ in what they are justified in doing. This is counterintuitive. (108)" But in our discussion over at Pea Soup, it was clear that they denied the following principle:
(JBJA) If S's belief that she should A is justified, it cannot be the case that S should B rather than A.
They cited cases where someone makes a mistake about the comparative weights of the reasons that bear on A-ing and B-ing as counterexamples to (JBJA). Since it seems being obliged not to do something means your doing it cannot be justified but you are justified in doing whatever you are obliged to do, I don't think on their view they gets to accommodate some of the intuitions internalists like to bash externalists with. You can deny (JBJA) and still adopt an internalist supervenience view, but you end up saying that the things that are counterintuitive from the internalist view.
Thanks, Jonathan. This is very nice. Maybe we were too hasty here. I'll have to think about it. But what about this:ReplyDelete
Take a subject, S, who at t0 is justified in believing that p and for whom p justifies S in doing A.
At t1, raise the stakes so that S is no longer justified in doing A. By JJ, the subject no longer is justified in believing that p.
Now, jack up whatever externalistic goodies you like. Make the externalistic goodies maximally wonderful (but keep the internal stuff the same). Unless the moderate externalist wants to say that there is no way to make S justified again externalistically, there's going to have to be a point at which S gets justified again. Say that, at t2, S reaches that point. So, at t2, S is justified in believing p. By JJ, then, it looks like p is warranted enought to justify S in doing A, again. And I don't see why anything else would stand in the way, here, since p actually justified S in doing A at t0. But I'm not sure, yet. So, p does justify S in doing A again. So, at t2, S is justified in doing A.
At t1, S isn't justified in doing A. At t2, S is justified in doing A. S has the same internal goodies at t1 and t2. So, there's the difficulty. All that's needed, I think, are two assumptions (maybe three). 1) Moderate externalism allows raising stakes to change whether p is warranted enough to justify. 2) Moderate externalism allows sufficiently improved external stuff to change unjustified propositions to justified ones. 3?) Nothing else stands in the way, once the unjustified proposition becomes justified, of the proposition justifying again.
They all seem like pretty plausible constraints on a plausible moderate externalism to me. I think maybe this is what we were driving at.
(Side note: we argue for your JJ* in the second half of the chapter.)
We do claim that moderate externalists who accept JJ “have to say” subjects internally alike can differ in what they are justified in doing. There is no strict entailment here. But it could still be that these theorists “have to say” this insofar as there is a very good argument, with plausible and seemingly neutral premises, from JJ + moderate externalism to the conclusion about action. Jeremy gives one such line of reasoning. I'll give another.
One doesn’t have to think that the converse of JJ is true – that is, that, in general, only what one is justified in believing can justify one in doing something – in order to think that there are particular cases in which, because of the situation in the case, one needs to be justified in believing a particular proposition in order to be justified in performing a certain action.
There are cases – particularly certain high stakes cases in which the crucial issue is whether p -- in which one must *at least* be justified in believing p if one is to be justified in the action. Some people would say you need something better than just justification to believe or even knowledge -- you need certainty, or whatever. Pick some such High case. Suppose p here is *the bank is open Saturday*. Suppose the subject has done sufficient checking so that he is justified in believing *the bank is open Saturday*. Given the relevance of this proposition to the question of what he should do, and given JJ, *the bank is open Saturday* will then justify him in planning to come back Saturday, rather than waiting in line today. Call this case High 1.
Next, given moderate externalism, it should be possible to keep things internally the same but vary the externalistic factors in such a way that the subject is no longer justified in believing the bank is open Saturday (holding fixed the actual as well as the perceived stakes, as well as the suite of options available to the agent -- which hopefully means we can leave to one side the sorts of "ought implies can" concerns that Clayton and I discussed on Pea Soup). This is High 2. In High 2, as in High 1, in order to be justified in planning to come back Saturday, the subject needs at least to be justified in believing the bank is open Saturday. So, since the moderate externalist will have to say that the subject in High 2 isn't justified in believing this, the moderate externalist will also have to say he isn’t justified in planning to come back Saturday. (JJ didn't enter in here, but it did in the case of High 1.)
So, if all this is right, there are very plausible (and neutral) assumptions which together with moderate externalism + JJ will have the consequence that there are pairs of cases that are internally alike (and alike in the suite of options available to the agent) but differ in what the subject is justified in doing.
Thanks for all these comments!ReplyDelete
Jeremy: I'm not sure why I should accept that improving the external stuff is going to make the difference we need in these cases. Let's fill in some details of your schema. I'll switch from different times to different worlds to avoid diachronic complications; I don't think that matters. Switch them back if you want. In w0, I'm justified in believing that p: [the frozen lake can support a hundred pound bag]. Let's suppose I just saw a hundred pound bag slide across another lake that looks pretty much the same. p justifies me in doing A: [sliding this hundred pound bag across the lake]
Now w1 is like w0, but with higher stakes. My friend is going to shoot me if the bag falls through the ice. In w1, I'm not justified in doing A. By JJ, I'm also not justified in believing p.
Now you want to consider a w2, in which I'm intrinsically just like I am in w1, but with more favorable external conditions. I'm extra super reliable, and the skeptical possibilities are really really far away, and all the lakes have the same thickness of ice, and whatever. You think it's clear that an externalist should think there's a w2 like this in which I'm justified in believing the lake can support the bag, even though there's a friend holding a gun to my head. I just don't see why an externalist has to think that, especially if he's committed to JJ.
Matt: why do we need to accept that there are cases in which being justified that p is the only thing that can justify a given action? That does not sound particularly plausible to me. In the case you describe, it seems that there are many possible ways to justify that action. For example, being justified in believing that the way to maximize expected value is to plan to come back Saturday would, I think, justify so planning.
The internalist has lots of ways for the subject to get justified again once the stakes are raised. For example, in most all of the cases in the literature, the subject can check further, get more evidence, and get justified again. By JJ, the subject then gets justified in acting again. But the moderate externalist, if you're right, is in this really weird position: once justification for belief gets lost (because of raised stakes), no external improvements can get that justification back. Do you want to say that, for the moderate externalist who accepts JJ, it's plausible that only low-stakes subjects can be justified externalistically in believing?ReplyDelete
I don't see what the worry is here, Jeremy. I think that externalists have all the same resources that internalists do for these sorts of issues. If the stakes go up, you can lose justification; you can gain justification again by checking further.ReplyDelete
I don't know what to make of the closing question: "Do you want to say that, for the moderate externalist who accepts JJ, it’s plausible that only low-stakes subjects can be justified externalistically in believing?"
What's the word 'externalistically' doing here? Of course externalists needn't think that you can't be justified in believing in high-stakes cases. And once we say that, I don't understand what question remains about whether subjects can be 'justified externally'. They're justified, and this matter isn't settled entirely by their internal states.
Internalists get to say that making purely internal goods as great as possible, the High subject gets justified again. If you're right, externalists don't get to say that making purely external goods as great as possible, the High subject gets justified again. That seems a point in favor of the internalist.ReplyDelete
First: I don't see why that's an advantage for the internalist. Why would the externalist want to be able to say that you can justify the High subject with purely external changes?ReplyDelete
Second: even if you're right that there's a point in favor of internalism here, that's neither here nor there; my present point is that externalists don't face the particular consequence claimed in your book, not that externalism is in general better than internalism.
I guess I take as a desideratum that High subjects can be justified in believing. What does that justification amount to? According to the moderate externalist, it amounts to having sufficiently good externalistic stuff -- reliability, etc. If jacking up the purely external stuff can't make the subject justified, it looks like the moderate externalist will be forced to say that the High subject can't be justified.ReplyDelete
Of course, I suppose the moderate externalist can allow mere improvements to internal goods to make High justified. But it sounds, here, like the moderate externalist is adopting an internalistic theory of justified belief for High subjects. That seems like a problem.
The only ways to avoid this problem that I can see are to reject JJ or accept that purely external differences can make a difference to what the subject is justified in doing.
Matt: why do we need to accept that there are cases in which being justified that p is the only thing that can justify a given action? That does not sound particularly plausible to me. In the case you describe, it seems that there are many possible ways to justify that action. For example, being justified in believing that the way to maximize expected value is to plan to come back Saturday would, I think, justify so planning.ReplyDelete
I wasn't saying we need to accept the claim that *being justified that p* justifies the action. I wasn't saying anything about the justifier -- the justifying reason. I was saying only that there are certain cases in which one needs to be justified in believing p if one is to be justified in the action. Sometimes, especially when the stakes are high, you got to have really good evidence, strong justification for a proposition p -- enough for being justified in believing p -- in order to be justified in performing a certain act. You will need really strong evidence that the bank will be open Saturday, say -- enough to be justified in believing (or know) this -- in order to be justified in planning to come back Saturday. You will need this strong justification in order to have either a reason concerning actual utility or a reason concerning expected utility reason. In the second part of the argument I gave in the previous comment (the part dealing with the case I called High 2) there is no reference to what does the justifying and no use of JJ.
Jeremy, I really don't see the issue here. What it is to be a moderate externalist is to think that not everything relevant to justification is internal. There's no tension at all in the idea that some things relevant to justification are internal.ReplyDelete
Matt, I think there's room to deny that in High 2, one need be justified in believing that the bank will be open in order to justifiably wait until tomorrow. Suppose I justifiably believe that given my practical interests and time constraints, the expected value of waiting until tomorrow is positive. That looks like enough to me.ReplyDelete
The thing is that in High 2 in order to have the expected value reason you'll need really high probability for p. Here's the expected value reason:ReplyDelete
EV(waiting till tomorrow) > EV(standing in line today).
This boils down to the claim that the first sum below is greater than the second:
Pr(it's open tomorrow)V(waiting till tomorrow when it's open tomorrow) + Pr(it's not open tomorrow)V(waiting till tomorrow when it's not open tomorrow)
Pr(it's open tomorrow)V(standing in line today when it's open tomorrow) + Pr(it's not open tomorrow)V(standing in line today when it isn't open tomorrow).
The only way to know or have good reason to think the first sum is greater than the second, in a standard High 2 kind of case, is to know or have good reason to think Pr(it's open tomorrow) is very very high -- surely high enough for justified belief by most fallibilist standards.
Why is this? Because V(waiting till tomorrow when it isn't open tomorrow) is very very low, whereas V(standing in line today when it is open tomorrow) isn't all that low. So the probability for *it isn't open tomorrow* needs to be tiny, and so the probability for *it's open tomorrow* needs to be high.
Matt, I agree with all of comment 13, but I don't see why it's relevant. Remember, I'm arguing that the combination of moderate externalism and (JJ) is not, as you say it is, implausible. It's not part of my defense of externalism to assume fallibilism. As you say, if you're a fallibilist, then it looks like the high probability should suffice for justified belief. The argument of the book is that this idea is inconsistent with plausible principles along the lines of (JJ). I'm not denying that; I'm inclined to think that something along those lines is probably right. I just don't see that this has anything to do with externalism.ReplyDelete