What is Knowledge?

Radical scepticism

we don't know nearly as much as we think we do the view that knowledge is impossible

Sceptical hypotheses

"Look, given that these scenarios are indistinguishable from normal life, you can't possibly say that they don't obtain. You can't possibly rule them out. But insofar as you can't rule them out, well then you can't possibly know anything about your normal life either, because of course, for all you know, you could be a victim of the sceptical hypothesis. "

Corollary

/kəˈrɒləri $ ˈkɔːrəleri, ˈkɑː-/ something that is the direct result of something else corollary of/to

Epistemology

/ɪˌpɪstəˈmɒlədʒi $ -ˈmɑː-/ the part of philosophy that deals with how we know things, how firmly we can know things etc

Knowledge-that

1. Knowledge requires true, you cannot know a falsehood 2. Knowledge also requires belief Knowledge is a relationship between a person and a fact and the relationship is at root one of belief. If you believe that something is the case and it is the case, then that puts you in the market for knowledge. PS knowledge doesn't require infallibility or certainty

Conclusion 2

1. The first is that knowledge isn't justified true belief. We thought it was, it looked very plausible that it might be, but the moral of the Gettier-style cases is that it can't be because you can have justified true belief and yet your true belief can simply be a matter of luck. And you don't get to knowledge through luck. 2. The second conclusion is that it's not obvious that you can simply add something to the justified true belief account of knowledge to solve the problem. It's not as if there's just some obvious way of adding an extra condition to the classical account to make it avoid Gettier-style cases. 3. That leads us to a third and quite profound conclusion, which is that therefore it's not that obvious what knowledge is.

Classical account of knowledge

Accommodate these intuitions about knowledge: that knowledge is getting things right in a way that's not lucky and that knowledge requires ability on the part of the subject. The idea is that when you know you satisfy three conditions: 1. You have a belief. 2. The belief is true. 3. And you have a justification for that belief, where this means that you can offer good reasons in support of why you believe what you do. Think about our two jurors again. The juror who forms his belief simply on the basis of prejudice - he has no good reasons that he can offer in support of what he believes. In contrast, our juror who sifted through the evidence and has come to appropriate conclusions that this person must be guilty - he can offer all kinds of good reasons in support of his belief. He is justified in believing as he does.

Anti-luck intuition

It's not a matter of luck that you get things right, it's because our juror formed his belief in the right kind of way and that's why he has got a true belief.

Ability intuition

It's that when you know, you get to the truth through your abilities. So think of our juror who has sifted through the evidence.

Ability knowledge

Know-how

Gettier counterexamples

Knowledge cannot be merely justified true belief. It simply is not possible. It is just a matter of luck that their belief is true.

Propositional knowledge

Knowledge-that. A proposition is what is expressed by a declarative sentence, i.e., a sentence that declares that something is the case. For example, the sentence 'The cat is on the mat' is a declarative sentence, because it declares something that may or may not be the case. I

Responding to Gettier-style cases

Patching up the classical account - no false lemmas (assumptions)

The brain-in-a-vat sceptical argument

Radically false beliefs. And yet their experiences are indistinguishable from the experiences we're having right now, which one would hope aren't brain-in-a-vat-type experiences.

Conclusion 3

1. We've looked at the problem of radical scepticism, which is the view that we don't know nearly as much about the world around us as we think we do. In fact, it's the view in its most extreme form that maybe we don't know anything at all. 2. We've seen that radical scepticism makes essential use of radical sceptical hypotheses, which are scenarios which are indistinguishable from normal life but where we're radically in error. 3. And we've seen that if we are genuinely unable to rule out the sceptical hypotheses then the sceptic seems to be right in saying that it's not altogether obvious how it is that we can know what we think we know about our environment. That is, the sceptical argument starts to look quite compelling.

A formula for inventing Gettier-style cases

1. take a belief that is formed in such a way that it would usually result in a false belief, but which is justified nonetheless. 2. make the belief true, albeit for reasons that have nothing to do with the subject's justification

Epistemic vertigo

When you start to reflect on the nature of knowledge, when you start to, as it were, "ascend" into a reflective mode of thought and start to think about what knowledge is and what is the extent of our knowledge, it ceases to become all that obvious that we really do have as much knowledge as we think we do. And this is the problem of scepticism. 1. I don't know that I'm not a brain-in-a-vat. 2. If I don't know that I'm not a brain-in-a-vat, then I don't know very much. 3. So, I don't know very much.