Moore on scepticism

[By Alex Gregory]

I volunteered to do a little guest blogging over here whilst Richard has work to do. I usually post at my blog over at atopian.org, on a combination of ethics and political philosophy, with some (mainly British) current affairs stuff mixed in. I may well do a post or two on some of that philosophy here as well, but for today I wanted to explore some other philosophy type stuff that I don't feel my own blog is the place for.

Here's a pair of apparently sound and valid arguments:

The no-knowledge argument:
1) No matter how small my odds of winning the lottery, I do not know that I will not win.
More generally: 2) I cannot know something if there is any possibility that I could be wrong.
3) I cannot rule out the (unlikely) possibility that I am dreaming, or continually misled by some supernatural entity, etc.

From (2) and (3):
Conclusion: 4) I do not know anything.

That's apparently compelling, and somewhat worrisome. But it gets worse. Here's argument number two:

The no-justification argument:
a) In order for any belief to be justified, the evidence must uniquely favour that belief.
b) All of the evidence available fails to distinguish the belief that reality exists roughly as we experience it from the belief that I am dreaming, or am continually being misled by some supernatural entity, etc.

From (a) and (b):
Conclusion: c) I have no justified beliefs.

Both of those argument are pretty worrying once you really understand the power they hold. There's an easy Moorean response though. Here are two equally valid arguments:

The knowledge argument (I've omitted the original premise (1) for brevity):
1') I know some things.
2') I cannot know something if there is (any) possibility that I could be wrong.

Conclusion: 3') I can rule out the possibility that I am dreaming, or continually misled by some supernatural entity, etc.

The justified argument:
a') I have some justified beliefs.
b') All of the evidence available fails to distinguish the belief that reality exists roughly as we experience it from the belief that I am dreaming, or am continually being misled by some supernatural entity, etc.

From (a') and (b'):
Conclusion: (c') It is not the case that in order for any belief to be justified, the evidence must uniquely favour that belief.

Since these arguments are equally valid, the real question is whether the no-knowledge and no-justification arguments are more sound than the knowledge and justified arguments. Further, since they share a premise each, then the question is which of the remaining premises we have more confidence in. For the first:
3) I cannot rule out the (unlikely) possibility that I am dreaming, or continually misled by some supernatural entity, etc.
or:
1') I know some things.

And for the second:
a) In order for any belief to be justified, the evidence must uniquely favour that belief.
or:
a') I have some justified beliefs.

And, of course, your standard Moorean will claim that our confidence in (1') and (a') is higher than our confidence in (3) and (a). Therefore, so they claim, it's the anti-sceptical arguments we should hold, not the sceptical ones.

Sorry to those familiar with this stuff - I just wanted to make clear both the power of the original arguments, and the simplicity and apparent power of the Moorean reply.

One way in which some people dismiss the Moorean reply is as some kind of conversational inpropriety. There is at least some form of oddness about Moore's response. However, either I'm missing something, or this is a very weak defence of scepticism. The way the worry is being phrased suggests that the only problem for Moore is simply the temporal order that the arguments have come in. Why, if only he'd been born earlier, then we'd be able to accuse the sceptic of that same conversational inpropriety! No, this objection to Moore will not work.

But there's a better reason to be worried about the Moorean reply. In both of the sceptical arguments, the premises provide some degree of an explanation for the conclusion (more than simple entailment). They show us why it is that we don't know anything, or why we don't have justification. In both cases, it's the worry about the possibility of alternatives ways that reality could be that would generate a similar appearance for our point of view.

In contrast, the Moorean anti-sceptical arguments don't really explain their conclusions, they merely state them. In the first, we haven't been given any explanation of why it is that we can rule out these possibilities. In the second, we haven't been given an explanation of why justification doesn't require our being able to distinguish reality from alternatives.

This doesn't make Moore wrong as such, but merely means that we need some further discussion of how exactly the conclusion is true. (Some people, of course, try to do exactly this. When Putnam provides a transcental argument against scepticism, it's intended to provide an explanation (based on semantics) as to why we can rule out certain sceptical possibilities as true.)