EPISTEMOLOGY-lec 6

Question 1

Fallibilism, infallibism, and scepticism

Answer 1

Definitions:

‘Infallibilism’ about knowledge is the view that S knows that p only if S has
justification/evidence for the belief that p that is incompatible with the belief’s falsity.

‘Fallibilism’ about knowledge is the view that S might know that p even though S’s justification/evidence is compatible with p’s falsity.

‘Scepticism’ about a given subject matter is the view that we can have no knowledge about the subject matter.

Question 2

Problems for infallibilism

Answer 2

It seems to set the standards for knowledge too high,
opening the way for widespread scepticism.

• If we say that knowledge is justified true belief, and
  that a belief is justified iff, if it is true it counts as knowledge, the ‘setting the standards too high’
  problem extends to the case of justified belief, and we end up with a view on which our best belief-forming methods do not justify the beliefs they generate.

Question 3

Problems for fallibilism

Answer 3

It seems to leave us saying apparently contradictory
things like ‘I know that I have a class at noon on
Tuesday, even though all my evidence leaves it open
that I don’t.’
- It seems to trample upon the difference between
knowledge and merely lucky true belief: if your
justification leaves the possibility that not-p open, why
is your belief that p, if true, not just luckily true?

Question 4

Epistemically relevant alternatives

Answer 4

HOWEVER, the definitions of ‘fallibilism’ and ‘infallibilism’ both appeal to the notion
of compatibility. The notion of compatibility requires explanation in terms of the notion
of possibility: in general, conditions X and Y are compatible iff it is possible for them
both to obtain at once (and incompatible otherwise).

Question 5

relevant alternatives’ account of knowledge

Answer 5

S knows that p iff S believes that p, and p is true in every epistemically relevant world
that is compatible with S’s evidence/justification

According to this kind of view, you know that p only if your evidence makes you
infallible about p across the epistemically relevant ways the world might be.
And now we can see one way to maintain that a belief for which the subject has only
defeasible justification can count as knowledge. Because the justification is defeasible, it
fails to eliminate some ways the belief might fail to be true. The belief counts as
knowledge as long as none of these ways is epistemically relevant.

Question 6

Contextualism

Answer 6

‘Contextualism’ in epistemology is the view that
a) S knows that p iff S believes that p, and p is true in every epistemically relevant world
that is compatible with S’s evidence/justification, and
b) which worlds are epistemically relevant varies with context.
In intuitive terms, the contextualist thinks that to say that a true belief counts as
knowledge is to treat it as reaching a standard of evaluation, and that, like other standards
of evaluation, this standard can shift. (Compare – Eleanor is tall for a two year-old. Helen Clark is
famous for a politician from New Zealand.) For example, one suggestion might be that the
standards for evaluation are higher in scientific inquiry than they are in everyday life: to
be justified in adding p to a scientific theory, you would need evidence that rules out even
very very very unlikely non-p scenarios; for everyday life, you just need evidence that
rules out very very unlikely ones.
But there is an open debate about whether we should say that epistemic relevance varies
with context, and if so, which features of context should be recognised as making a
difference.

Question 7

Lewis’s version

Answer 7

1 The actual world is always relevant.
2 A possibility that the subject believes to obtain, or ought (relative to available evidence)
to believe to obtain is always relevant.
3 If possibility A saliently resembles possibility B, and A is relevant (on the basis of 1 or
2), B is relevant.
4 Possibilities involving the failure of reliable belief-forming mechanisms are irrelevant.
5 Possibilities involving the unrepresentativeness of samples that meet reasonable tests
for representativeness, or the failure of the best explanation to be the right explanation are
irrelevant.
6 Possibilities that most speakers in our community ignore all the time are irrelevant.
7 An attended possibility is always relevant.
QUESTION – WHERE IS LEWIS GETTING THESE RULES FROM? We have seen the argument for
1. In effect, Lewis is just proposing the others (though look at the reading for some
arguments in their favour). For each of 2-7, there is a live debate about whether it should
be accepted.
Note that 4 gets us the result that, as long as the ordinary method of forming perceptual
beliefs in fact is reliable, the possibilities of illusion and hallucination do not undermine
the status as knowledge of true perceptual beliefs

Question 8

Scepticism and the Rule of Attention

Answer 8

Lewis thinks that 7, the ‘Rule of Attention’ lets him explain both why we do not have to
worry about scepticism in everyday (or scientific) life, and why the threat of scepticism
seems so problematic when it comes to trying to explain how we can have knowledge of
the world around us:
a) Our best evidence cannot rule out sceptical scenarios, for example, the scenario in which you are a
brain in a vat and all your experiences are caused by electrical stimulation.
b) In ordinary contexts we can know many ordinary (and scientific) things (because in
ordinary contexts sceptical scenarios are not epistemically relevant, so the fact that our
evidence does not eliminate them is no threat to our ordinary claims to know).
BUT
c) When we come to doing epistemology, we attend to sceptical possibilities. These
possibilities then become relevant. And once they are relevant, they cannot be eliminated
by any of our evidence. So in an epistemological context you count as having very little
knowledge (depending on the strength of the sceptical hypotheses you are attending to).