Here's a schematic version of the skeptical arguments we've been looking at so far:
1. You can't rule out the possibility that you're a BIV, or in the Matrix, or deceived by an evil demon, or..., even though those are possibilities you recognize to be incompatible with p.
2. You can only know that p if you can eliminate or "rule out" all the alternatives you recognize to be incompatible with p.
3. So you don't know that p.
The Relevant Alternatives Theorist is someone like Austin who denies 2. He says you don't have to rule out all the alternatives to P, or even all the things you recognize to be alternatives. You just have to rule out the alternatives that are somehow "relevant."
What makes an alternative "relevant"? So far, we've encountered several different stories about this.
We could say that relevance depends on facts about what the knower believes or has evidence for believing. For instance, we could say that the grebe possibility is relevant just in case the knower believes there to be grebes around, or has evidence that there are grebes around. This is what Austin thinks makes a possibility relevant.
Or we could say that relevance is affected by facts about the knower's environment, even if the knower is unaware of those facts. For instance, we could say that whether the grebe possibility is relevant just depends on whether there are grebes in the neighborhood.
Or we could say that whether some alternative counts as relevant doesn't depend so much on facts about the knower; rather it depends on facts about the conversational setting in which knowledge is being ascribed, or in which the knowledge-claim is being assessed. For instance, if we're talking about whether Julius Caesar knew he had hands, in one context we might want to count hypotheses like BIVs and evil demons as irrelevant, and in another context we might want to count them as relevant. This depends upon us, and our interests and purposes, not upon facts about Caesar. This is the kind of story a Contextualist tells.
Words like "I" and "now" are clearly context-sensitive. What person or time they pick out depends on the context in which they're uttered.
Similarly, one might argue that "big" is context-sensitive. If we look at Mighty Mouse scurrying about with a bunch of other mice, we might say "He sure is big." If we look at Mighty Mouse scurrying around with a bunch of kangaroos, we'd probably say, "He sure is small." Perhaps we're saying something true in each case. In the first case, what we want to say is that Mighty Mouse is big for a mouse. In the second case, what we want to say is that Mighty Mouse is small for a land animal, or something like that. The comparison class is supplied by the speaker's intentions and the audience's expectations, and these vary from context to context.
One could also give a Contextualist account of words like "flat" and "empty." One could say that what counts as flat varies from context to context. When we want a flat surface to calibrate our machine tools, the Kansas highway doesn't count as flat. When we want a flat surface to land our damaged airplane, the Kansas highway does count as flat. What "flat" means depends on the intentions and expectations of the people engaging in the conversation.
This is different than the story we saw Stroud giving about words like "flat." Stroud was claiming that it's never literally true to call the Kansas highway flat, but it might sometimes be appropriate or reasonable to call the highway flat, for instance, if you're looking for a place to land your damaged airplane. The highway is close enough to being flat for your practical purposes.
The Contextualist, on the other hand, would say that in some contexts it really is literally true to call the Kansas highway flat. Just as in some contexts it really is literally true to call Mighty Mouse big. In some contexts the little irregularities in the highway surface don't count; they're just too small. In those contexts, the highway has no bumps in it that are big enough to count. So it's literally true that it's flat.
I want you to understand the difference between these two views. If you feel like, "Well how could you decide which view is right?" that's a perfectly sensible reaction to be having. It is hard to tell what kinds of evidence would show the one view to be right and the other view to be wrong. This is a topic of much controversy in contemporary philosophy of language. But right now we don't need to decide which of these is the right view. We just need to understand the difference between the two views.
The Stroud view says it never is literally true to say that the highway is "flat." But it would be very complicated and tedious to always speak the literal truth, and still get across the things we want to get across. Suppose the copilot has control of your plane and it's about to crash and he shouts "Do you see any flat place for us to land?" and you look out the window and a bit off to the left you see an empty Kansas highway. If you just say "No," because the highway is not really literally flat, your copilot won't know to steer to the left and you'll crash and die. If you say "No, there's no place that's really flat, but there's a highway over there which is pretty clo--" Whoops. Took too long. It makes the most sense just to say "Yes, over there!" even if what you're saying is literally false. It's literally false but for practical intents and purposes it's the most reasonable thing to say. That's Stroud's view.
On the Contextualist view, on the other hand, in a context like the one I've described, it really is literally true to call the highway "flat." Just as it can sometimes really be literally true to call Mighty Mouse "big," if it's clear in the context that you mean big for a mouse. So too it can really be literally true to call the highway flat, if it's clear in the context that little bumps in the asphalt are too small to count.
So that's what Stroud and the Contextualist would each say about words like "flat." They'd say similar things about words like "empty." And this is also what they say about words like "know."
A Contextualist about knowledge says that what "know"means varies from context to context, just like "big" and "flat" and "empty." The general story is: "S knows that p" means that S truly believes that p and S has evidence that's good enough to rule out all the relevant alternatives--but in different conversational settings, the Contextualist thinks, different alternatives count as relevant. When you're talking to your butcher, things like BIVs and the Matrix and perfect dreams aren't relevant. So in contexts like that you can truly say that you know you have hands. When you're talking to the skeptic, on the other hand, the set of relevant alternatives is different. In a context like that, things like BIVs and evil demons may become relevant alternatives, and since you can't rule those alternatives out, in those contexts it would be false to say that you know.
Stroud on the other hand says that it's never literally true that you know you have hands. Your evidence may be good enough that you're close enough to knowing for all practical intents and purposes, it may be practically appropriate or reasonable for to say that you know, but still, it's never really true that you know. It's not true that you know because there are some alternatives, like being a BIV, which your evidence does not enable you to rule out. (In the article "Skepticism and Everyday Knowledge Attributions," Cohen calls this "the pragmatic view.")
Stroud interprets Austin as a kind of relevant alternatives theorist. But Austin is a little bit different than the Contextualist. Like the Contextualist, Austin thinks that knowing you have hands only requires you to rule out some alternatives, not every alternative. Like the Contextualist, Austin also thinks that whether you know you have hands can vary from context to context. But the Contextualist thinks that what determines what alternatives are relevant are the intentions and expectations of the people involved in the conversation. Austin thinks that what determines what alternatives are relevant is the kind of evidence that you possess. On his view, you only have to rule out those specific alternatives you have some reason to believe do obtain. Hence, the guy in Pollock and Cruz's story, who has evidence that he's a BIV--he has to rule out the possibility that he's a BIV. We on the other hand don't have any evidence that we are BIVs, so we don't have to rule that possibility out, even if we're talking to a skeptic.
Dretske is also some kind of Relevant Alternatives Theorist. Unlike Austin, Dretske thinks alternatives can be relevant even if you have no evidence that they're true.Going back to our list of what makes an alternative relevant:
Austin: relevance depends on facts about what the knower believes or has evidence for believing.
relevance is affected by facts about the knower's environment, even if the knower is unaware of those facts.
Contextualist: whether some alternative counts as relevant doesn't depend so much on facts about the knower; rather it depends on facts about the conversational setting in which knowledge is being ascribed, or in which the knowledge-claim is being assessed.
It's sometimes hard to tell whether Dretske is defending choice 2 or choice 3. Cohen in his paper "Skepticism, Relevance and Relativity" tries to separate these different choices.
Recall the Closure Principles about knowledge that we discussed earlier. For example:
If you know that P, and you know that P logically entails not-Q, then you have to know (or at least be able to know) not-Q too.
At first glance it looks like the Relevant Alternatives Theorist will be rejecting Closure. Closure tells us that you have to know to be false everything which is (or which you know to be) an alternative to P; whereas the Relevant Alternatives Theorist says you only have to know to be false those alternatives which are relevant.
And sure enough, Dretske's version of the Relevant Alternatives Theory does reject Closure. This comes out more in Dretske's paper "Epistemic Operators."
For example, Dretske claims that you can know that the animal in the pen is a zebra on the basis of evidence which does not enable you to know that the animal isn't a cleverly-disguised mule. So here we have a counter-example to Closure:
You know that the animal is a zebra.
The claim that the animal is a zebra is incompatible with its being a cleverly-disguised mule. (And you know this.)
Yet you don't know the claim that the animal is not a cleverly-disguised mule.
Dretske thinks that knowledge is closed under some known entailments. For example, he thinks that if you know that P&Q, then you know that P. (P&Q logically entails that P.) He just thinks that Closure fails when it's a matter of knowing P, and knowing that P entails not-Q, but Q is not at the moment a relevant alternative to P. In such a case, Dretske thinks, you can know P even if you're not in a position to know not-Q. You can know it's a zebra in the pen even if you're not in a position to know it's not a cleverly-disguised mule. But if the possibility of its being a cleverly-disguised mule were to become relevant, then--since you can't rule it out--you would no longer count as knowing that it's a zebra in the pen.
However, matters are not so straightforward. After all, it's somewhat odd to deny Closure. It's odd to say that you could know that P, and know that P entails not-Q, but not be able to put these together and draw the conclusion that not-Q.
If you hold a Contextualist version of the Relevant Alternatives Theory, then you might be able to retain some kind of Closure Principle.
According to the Contextualist, Norm can say "Caesar knew he had hands" and Skepty can say "Caesar did not know he had hands," and they need not be disagreeing. They might both be right. It's just that what they mean by "X knew he had hands" is different, since the sets of relevant alternatives are different.
Similarly, when you say "I know I have hands" and the skeptic says "You don't know you're not dreaming," the Contextualist can say you're speaking in different contexts, with different sets of relevant alternatives. It's as if Tom were to say "I'm Tom" and Jerry were to say "I'm not Tom." There's no conflict there, just a difference in context.
With this in mind, the Contextualist can go on to insist that Closure holds within any single context. In any given single context, you either know that you have hands and that you're not dreaming, or you don't know that you're not dreaming and you don't know that you have hands, either. If dreaming is a relevant alternative, then you don't know either of these things. But if dreaming is not relevant, then you can know that you have hands, and you can also know that you're not merely dreaming.
So it looks like one can be a Contextualist and still accept the Closure Principle, after all.
However, there is a small snag. If we accept Closure, then we say that (in any single context) knowing that P requires you to know to be false all the alternatives to P. However, we want to conjoin this with a Relevant Alternatives Theory, so we say that (again, in that single context) knowing that P doesn't require you to eliminate or rule out all the alternatives to P. You know the alternatives to be false but you haven't ruled them all out. This shows us that we should distinguish between merely knowing an alternative to be false and having ruled that alternative out. Knowing that an alternative is false is easy to come by (when the alternative is irrelevant); being able to rule the alternative out is harder.
For example, so long as we're evaluating what you know in a non-skeptical context, a context where the possibility of dreaming is not among the relevant alternatives, then you count as knowing you have a hand, that you're standing up, etc., and you also count as knowing the consequences of these things, e.g., that you're not a handless student dreaming that she has hands. However, on nearly everybody's view it's impossible to ever "rule out" the possibility that you're dreaming. This is why Relevant Alternatives Theories seem so attractive. They say you can have perceptual knowledge without having to rule such skeptical possibilities out. So knowledge that you're not dreaming is easy to come by; but the ability to rule out the possibility that you're dreaming is hard to come by.
If you want to hold the view I've been describing, then--a kind of Contextualism that retains Closure--then you need to come up with some account of "ruling out" that makes ruling an alternative out harder than merely knowing that alternative to be false.
Here's another issue to think about. Suppose you're walking down the street talking to your friend on your cell phone and your friend says "Do you know whether it's raining on Nassau Street?" Since you're walking on Nassau Street you say "Yes." Now a skeptic has overheard your conversation, he butts in and says, "Hey remember the Matrix and so on. Now do you know whether it's raining in on Nassau Street?" Now that the Matrix is a relevant alternative, you no longer count as knowing things about your environment. So you say "No, I don't know." The skeptic says, "So before you knew but now you don't? Isn't that a strange theory?"
The best thing for the Contextualist to say about these kinds of cases is that the skeptical context doesn't just change the meaning of the present-tense claims "I know that P"; it changes the meanings of past-tense claims, like "I knew that P," too. So in the skeptical context, "I know the weather on Nassau Street " is false and so too is "I knew the weather on Nassau Street a minute ago." But in a non-skeptical context both of those sentences would be true. That's because the sentences say different things in the different contexts.
Compare: Yesterday you're in Maine and you say "It's cold here." Today you go to Tennessee where they're having a heat wave. You say "It's hot here today, and it was hot here yesterday too." Now yesterday you said "It's cold here" but today you're saying "It was hot here yesterday." Have you changed your mind? No, of course not. "Here" means different things in the two contexts. It doesn't matter that yesterday you were in Maine. You still interpret "here" according to what it means in today's context. That's Tennessee.
Similarly, the Contextualist will say, "know" means different things in non-skeptical contexts than it means in skeptical contexts. It means different things because the set of relevant alternatives is different in the two contexts. It doesn't matter if yesterday you were in a non-skeptical context. You still interpret "know" according to what it means in today's context. Hence, in a skeptical context, "Yesterday I knew that I have hands" comes out false; no matter what kind of context you were in yesterday.
Tim Williamson has an objection to the Contextualist that uses examples of this sort, where you're talking in one context about what's true in another context. Suppose you're in a skeptical context. So you say that "I know I have hands" is false. You can agree, though, that in the non-skeptical contexts, "I know I have hands" says something true. But now knowledge is factive; if there are any contexts in which "I know that P" says something true, then "P" has to be true in those contexts as well. So you should agree that in the non-skeptical contexts, "I have hands" also says something true. Now compare the non-skeptical context to your own present skeptical context. Is there anything that could make "I have hands" mean something different in the one context than it does in the other? No, it doesn't seem like there is. The Contextualist's view is that sentences involving the word "know" mean different things in different contexts, because the set of relevant alternatives can be different in different contexts. The Contextualist doesn't also say that any sentence involving words like "hand" has to mean different things in different contexts. So it looks like "I have hands" means the same thing in your skeptical context as it does in the non-skeptical context. So if it's true in the non-skeptical context, it has to be true in your context as well. Hence, you should agree that in your context, "I have hands" is true. Yet as we said at the beginning, you say that "I know I have hands" is false in your context. But this is very funny. It would be very funny to say "I have hands, but I don't know I have hands." Williamson takes this to be a point against Contextualism.
How satisfactory a reply to the skeptic does a Relevant Alternatives Theory really give us? The skeptic will just say, "You're begging the question against me, in claiming that my skeptical possibilities are irrelevant and don't need to be ruled out, if you're to count as having perceptual knowledge."
However, as Cohen points out in "Skepticism, Relevance and Relativity," the Relevant Alternatives Theorist can reply back to the skeptic: "Why should we accept your account of which alternatives are relevant and which are irrelevant? You're just begging the question against common sense, in claiming that those alternatives are relevant to the question whether we know."
We seem to have reached a stand-off. Both sides claim that the other side begs the question. How might this stand-off be resolved?
Well, we should distinguish two different sorts of anti-skeptical projects we might be engaged in.
The first project is to refute the skeptic using only premises that the skeptic will accept. (This is like playing "King of the Hill." Skeptic gets to start as the King, and we have too knock him off.) Perhaps this project is doomed to fail. Perhaps any premises we'd need to show that we have knowledge would be rejected by the skeptic as question-begging.
The second project is to set our own minds at ease about the skeptic's argument. The skeptic has an argument from premises we find initially plausible to a conclusion we find unacceptable. We can't just go on believing the premises but denying the conclusion. If we want to avoid being forced to accept the skeptic's conclusion, we've got to diagnose his argument and explain where it goes wrong, or explain why although the premises seem plausible they're really false. (Call this "explaining away the skeptic in ourselves.")
If this is our project, it doesn't matter so much whether we say things the skeptic won't accept. It's only necessary that we accept them. After all, we're only trying to set our own house of beliefs in order. We just want to show to our own satisfaction that we can retain our common-sense views about knowledge without falling into the skeptic's trap.
One natural way to think about the Contextualist's story is as follows. We have evidence for believing various things. And some of the things we believe are true. But if your evidence for P is very slight, that won't be enough for you to know that P, even if P happens to be true. So we have the question: how much evidence does it take for a true belief to count as knowledge?
Now the Contextualist will answer this question by saying, "That depends upon the context." In some contexts, having evidence that makes P 99% likely might be good enough for you to know that P. In other contexts, e.g., when we're thinking about lotteries and so on, 99% might not be good enough.
What the skeptic tends to do is to get us into contexts where the bar for knowledge is very high. The Contextualist acknowledges that in contexts of that sort we don't count as having knowledge. But he says that we shouldn't lose sight of the fact that in other, ordinary contexts, where the bar for knowledge is lower, our evidence might very well be good enough for us to count as knowing.
That story does have some plausibility to it. But the problem is that it requires you to have some evidence against the skeptic's possibilities. In ordinary contexts, that evidence should be good enough to know those possibilities don't obtain; though in skeptical contexts the bar is higher and there the evidence isn't good enough for knowledge.
But do we any evidence against the skeptic's possibilities? What is our evidence that we're not in the Matrix, or not being deceived by evil demons? We would be having exactly the same experiences even if those possibilities were true. So it's not clear whether we even have any evidence at all that those possibilities don't obtain. (This is a point the Blumenfelds made earlier.)
We need to think more about how the skeptic's arguments bear on issues about evidence and justification, not just knowledge. And we need to think about the relations between justification and knowledge. That is what we'll turn to next in the course.