| Knowledge | |
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Recommended Reading |
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Introduction |
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In
this section of the course we’re going to be talking about knowledge,
what it is, how to get it, whether it’s possible – all that sort of
thing. But before we go on to look at some arguments for extreme
skepticism, which say that we really can’t know anything, we should be
clear that we know what we’re talking about when we say that we’re
talking about knowledge. (That’s not quite the same thing as knowing
what it is, so we’re not going to be begging any questions by talking
about this in the introductory section.) When
we talk about having knowledge in English we can mean many different
things. That’s because, just as a result of historical accident, several
distinct but related concepts are named by the same word in English. This
isn’t the case in all languages, but we are going to be talking in
English, so we’d better be clear what we’re using the word to refer
to. There are traditionally held to be three different kinds of knowledge:
1. Knowledge by
Acquaintance, which is the sort of knowledge that we claim when we say
that: ‘I know Bob’ or ‘I know Robina;’ 2. Ability, which is
what we mean when we say that ‘I know French’ or ‘I know how to ride
a bike;’ 3. Propositional Knowledge, which is what we are claiming
when we say that ‘I know that Bob is a builder’ or ‘I know that they
speak French in It’s
only the last case that we’ll be interested in. We call this
‘propositional knowledge’ because it claims that we are in some sort
of relationship with a proposition. A proposition you should understand as
being some sort of abstract thing that is expressed by an actual
declarative sentence. The reason we want to talk about this abstract
object rather than the sentence that expresses it is because we don’t
want the content of knowledge to be confused with the manner of expressing
it. A sentence in English like ‘John is in the garden’ expresses the
same proposition as the French sentence ‘John est dans le jardin’, or
the Latin sentence ‘John est in horto’ or etc. We think it’s
absolutely clear that whatever it is I claim to know when I say ‘John is
in the garden,’ is the same thing that I would claim to know by claiming
that is the same belief as knowing that ‘John est dans le jardin’, or
‘John est in horto’ or etc.
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Knowledge |
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In
fact when we say that we know that P (where P stands for some proposition)
it is generally said that we are taking an attitude towards the
proposition P. Knowledge is thus said to be a Propositional
Attitude, one of several attitudes that we can take towards
propositions; such as hope, fear, despair, belief, … Now, one of these
attitudes seems to be very, very closely related to knowledge, that is the
attitude of belief. Knowledge seems to be a sub-attitude of belief:
whenever we claim to know something it is implied that we also believe
that thing. How can you know something that you don’t believe? It seems
impossible. But
if knowledge is a kind of belief then what are the characteristics that
separate it from just general belief? There is a standard answer to this
which is that for some belief to be knowledge it has to be true, and it
has to be properly justified. We can see immediately why truth gets in
there: you can’t claim to know something that isn’t actually true. It
would be impossible for anyone to know that the moon is made of green
cheese, because it just isn’t. It is impossible to know that the world
is flat, because it isn’t. Note that that doesn’t mean that people
can’t think that they know
that the Earth is flat, because obviously they can. In fact people can
have all sorts of false beliefs, which they think are knowledge (otherwise
why would they believe them?) but which are not knowledge. Knowledge
isn’t to be identified with whatever people believe that they know, only
with what they do know. But
true belief isn’t enough either. Suppose I decide that I will find out
what the temperature is by throwing a dart at a dartboard. One day it just
so happens that the number that that produces is the actual temperature,
say 20oC. And so I believe that it is 20oC and it
actually is 20oC. And
so I have a true belief. But nobody thinks that this is knowledge. We have
a phrase in English ‘Even a stopped clock is right twice a day’ that
makes something like the same point. We use this phrase when we think
someone has come to a conclusion or has a belief that happens to be true
using a seriously flawed method of belief fixing. In such a case we
don’t think that they know what they claim to know any more than the man
with a stopped clock knows the time even when his clock says 2pm and it is 2pm. That man is not justified
in his belief. Just so, we think that we need to have some justification
for our true beliefs before they can be classed as knowledge. The belief
and the fact that it is true can’t just be accidentally related, there
has to be some connection between the two that justifies us in believing
it. Thus
we arrive at the notion – which in one form or another is widely
accepted – that Knowledge is justified, true belief. Let’s
look at each part of this definition. We talk about Belief in the
Mind section, so it won’t be worthwhile going into the problems with it
here, and you can just use your naïve unphilosophical views of
‘belief’ for the time being; but looking at the concepts of Truth and
Justification in these last lectures makes a nice
symmetry with the first lecture’s Argument and Analysis
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Truth |
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You’ll
recall in the A&A lecture we talked about how to go about determining
whether arguments were good arguments, and central to that was the idea
that a good argument would get us to a true conclusion. But what exactly
are we claiming when we claim – as in a knowledge claim – that some
proposition is true? There are three classic positions. The Correspondence
theory, Coherence, and Pragmatism. We’ll look at these in turn. Correspondence The
correspondence theory is probably the one that is most in tune with the naïve
philosophical views of the common person. We generally take it for granted
that what makes a sentences true is the fact that the world is the way
that the sentence says that it is. So ‘Snow is white’ is a true
sentence if snow is white, because ‘snow is white’ says that snow is
white and there is a corresponding fact about the world; the fact that
snow is white. We might be inclined, therefore, to say that a sentence is
true if it corresponds to some fact about the world. That
is, in fact, just what the correspondence theorist of truth does say. But,
although we all think to begin with that we know what we’re saying when
we say that, a little bit of reflection reveals that we haven’t really
clarified the notion of truth at all, for now we have to answer the
question: what is it for a sentence to correspond to a fact? We know what
it means to say that a picture of a thing corresponds to the thing itself.
(Actually, we don’t, but we sort of think that we do.) It means that
some elements of the picture are in the same or systematically modified
relations to each other as are the parts of the object itself. So a
picture of a lion has a picture part depicting a head at one end and a
picture part depicting a tail at the other end, and a lion has a head at
one end and a tail at the other. But it isn’t obviously the case that
this is how we can understand the correspondence of sentences and facts.
It’d be hard to argue that the sentence ‘snow is white’ looks like
the fact that snow is white. Hard, I say, but some philosophers (Russell,
Wittgenstein) have given it a shot. The
picture theory to one side, any correspondence theory is going to have to
account for all sorts of strange situations that sentences describe but
that don’t look likely to be independent facts: things like, for
example, negative claims. If I say that the world is not flat, I am not
claiming that the world is any particular way, only that there are some ways that it is not.
What sort of fact does that correspond to? Or does it correspond to a
class of facts? Coherence Rather
than going on to look at the ways that defenders of the correspondence
theory have tried to save it from this sort of objection, we’ll move on
to the coherence theory. In this theory, the idea is that a proposition is
true if it coheres with all the other propositions that are held to be
true. Thus ‘snow is white’ is true because all the logical
implications of that statement – like ‘snow is not green’, ‘snow
is the colour of copier paper’, ‘water crystals are translucent to all
visible wavelengths of light’, and so on are also held to be true; and,
in fact, all the ways in which that statement can be connected to other
statements that are believed to be true or false make sense if ‘snow is
white’ is asigned the truth-value True. Logically speaking, the
statement ‘snow is white’ is consistent with all the other statements
expressing your beliefs. You cannot derive a contradiction from ‘snow is
white’ plus all your other beliefs. Note that one of the statements you
are going to hold at some stage to be true is that ‘I see snow and it is
white’, so there is a way to connect this to the actual way the world
is. But it’s a bit indirect and doesn’t depend upon a troublesome
notion of ‘correspondence.’ Coherence
theories also have their problems, of course, and the two major ones are
that (1) it’s almost guaranteed that some of the things that one
believes are inconsistent with some of the other things that one believes.
I, being an ignoramus in matters macroeconomic, may believe certain things
about balance of trade, or comparative advantage, but I may also believe
that classical economics gets the story about these things right, whereas,
unbeknownst to me, classical economists contradict my beliefs about the
balance of trade and comparative advantage. So I have an inconsistent set
of beliefs. But this means that for any sentence – like ‘snow is
white’ – I can derive contradictions, even if just from my beliefs
about economics. But this means, finally, that I can’t have any
true beliefs. That seems harsh. The
other problem is that if coherence does mean consistency as I’ve been
saying, then what is consistency? You can’t say ‘a set of sentences
are consistent if they can all be true together’ because now you’re
using the concept of truth to define the concept of truth, and that’s
viciously circular. So it might be that the idea of a coherence theory is
actually incoherent. Pragmatic A
third attempt to clarify the notion of truth is the idea of a pragmatic
defnintion of truth. This is the claim that ‘truth is what works.’ So,
‘snow is white’ is true because when one takes this to be true one is
able to interact successfully with the world. For example, one is able to
design cunning snow camouflage to fight your enemy in the Winter War;
whereas if one took ‘snow is green’ to be true, one would have less
success, and one would be an easy target, and one would be shot. But
this has many of the same problems as the coherence theory together with
some strong objections peculiar to it. For example, as long as the
Sun-centred theory of the solar system was less well-developed than the
Earth-centred theory, the Earth-centred theory will be the one which give
the best results and is thus the ‘true’ theory. But that seems wrong.
Surely the Earth-centred theory was always just not true.
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Justification |
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So
we have some difficulties knowing what we mean by truth. That’s going to
make some difficulties for understanding what we mean by knowledge when we
define that as justified, true belief. But let’s move on to see what we
can say about justification in that definition. Remember
that the point of the justification criterion is that it can be just a
coincidence that the belief that we have is a true belief; and we decided
that what was lacking was a good reason to have that belief. If we had a
good reason to believe a true thing then we would have knowledge. On the
other hand, most philosophers will also say that just because we have a
good reason to believe P, it doesn’t necessarily follow that P is true.
In the past, for example, people may have had good reasons to think that
the world is flat – after all, if it wasn’t flat then people would
fall off where it was sloping. If the only thing that counted as a
justification for a belief was something that made its truth absolutely
certain, then we wouldn’t need to have ‘truth’ in the conditions for
knowledge. We could just say knowledge is justified belief and the truth
of that belief would follow from its being justified. However, as we will
see when we look at some skeptical arguments later, infallibly justified
beliefs are very hard to come by. In fact asking for that condition may
remove the possibility of knowledge altogether. But that makes the whole
definition of knowledge rather pointless, and we are pretty sure we do
know some things – in
any sensible sense of the word ‘knowledge’. For example, I surely know
that I am standing in this room talking to you. It is therefore widely
accepted that justifications are fallible.
Apart
from fallibility/infallibility, there’s another characteristic of
justifications that is of interest. A theory of justification can be
either what is called internalist
or externalist. An internalist theory of justification is one in which
the properties which make a reason to believe something a justification
are properties that are purely internal to the subject. We’ll see some
examples in a second, but one way to think of this is to say that on the
internalist view it is possible for the subject to determine whether their
belief is justified or not by simple awareness of their own internal
states and processes. By contrast, for the externalist the existence or
otherwise of a justification is a judgement to be made from the omniscient
observer’s perspective. Whether a reason to believe (or a reason for
belief) is a justification depends upon real, objective properties of that
reason. There
are three classic views of justification that we’ll list here: reliabilist,
foundationalist, and coherentist. Reliabilism The
reliabilist is an externalist. According to his theory, we are justified
in a true belief if the belief is properly formed by means which reliably
lead to true beliefs – whether of not the believer realises that that is
the case. For example, we are justified in believing that we are in a
lecture hall at the moment because that belief is formed by perceptual
mechanisms and reasoning processes that in almost all cases result in true
beliefs being formed. That’s fairly easy to understand, and we’ll see
how this sort of thing is attacked by Descartes in the next lecture,) but
consider that if I happened to be a clairvoyant who could close his eyes
and see what was going to happen in the future, and if what I said was
going to happen really did almost always happen, then, no matter whether
or not I have any idea of what goes on in my head when I close my eyes to
take a clairvoyant ‘reading’, the reliabilist would say that I have
knowledge, because the process is really
reliable. Others,
however, think that the very fact that that sort of oracular pronouncement
can be classed as a piece of knowledge is evidence that the reliabilist
position must be missing something. Presumably it’s missing something in
the nature of a connection between the formation of the belief and the
awareness of the reliability of the formation. It doesn’t count as
knowledge unless the believer knows how the justifictation works – which
some might say is exactly what was mean by requiring there to be a
justification in the first place. So
we seem to need to have an awareness of the way that the justification
proceeds. This suggests that justification should be understood as an
internalist process, and that justification is a judgement that can be
made by the believer from his own resources. There are various ways that
this can be thought to occur. Foundationalism In
the first place we could claim that there are certain fundamental, or
basic beliefs, and that other beliefs are derived from them by some
fallible but powerful method. From what we said in the previous lecture on
Arguments and Analysis, the other beliefs must be justified either as
deductively valid consequences of those beliefs or as inductively strong
consequences (in which case they’re not indefeasible.) The class of
basic beliefs, which are presumably self-justifying or justified by some
method other than deduction or induction from other beliefs, is a
stumbling block here. It is hard to know what exactly can go into this
class, and until we get something in there we can’t even start to build
up knowledge by deriving other beliefs from that set. When we look at
Descartes in the next lecture we’ll see what he takes to be a basic
belief that can get us started. Coherentism On
the other hand, if we like the idea of beliefs being supported by other
beliefs, then we might prefer a type of coherence theory of justification
– which is rather similar to the coherence theory of Truth that we
looked at above. In this case we say that a belief is justified if it
coheres with the other beliefs that a subject holds, and that there are no
beliefs that are justified outside this network of beliefs. The
difficulty with this is, however, that a subject may have a set of beliefs
that are all what we would call false and yet are absolutely coherent. For
example, someone who has immersed themselves in a fictional world –
perhaps something like Second Life (which is a type of virtual world) –
could have thoroughly coherent beliefs which are all false about the
world. The intuition that we have here is that there needs to be some
connection beyond the mere network of mental states in order for a
justification for beliefs about the world to be legitimately a
justification for beliefs about the world. And so we are brought back to
the externalist position: that there is something true and beyond the
subject that is essential for a justification.
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Gettier Problem |
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Of
course, all this has been based on the idea that justified, true belief is
a satisfactory analysis of knowledge, and all we have to do is to make
sure we know what is meant by true, and justified, and belief; but even
this was disputed by a very famous and very short paper by Edmund Gettier
in 1963. He gave cases in which a belief could be true, and justified, and
yet we would still not think that there was knowledge involved. The paper
is so succinct that I can give the second of his examples just as he
presented it: Let
us suppose that Smith has strong evidence for the following proposition: f.
Jones
owns a Ford. Smith's
evidence might be that Jones has at all times in the past within Smith's
memory owned a car, and always a Ford, and that Jones has just offered
Smith a ride while driving a Ford. Let us imagine, now, that Smith has
another friend, Brown, of whose whereabouts he is totally ignorant. Smith
selects three place names quite at random and constructs the following
three propositions: g.
Either
Jones owns a Ford, or Brown is in h.
Either
Jones owns a Ford, or Brown is in i.
Either
Jones owns a Ford, or Brown is in Brest-Litovsk. Each
of these propositions is entailed by (f). Imagine that Smith realizes the
entailment of each of these propositions he has constructed by (f), and
proceeds to accept (g), (h), and (i) on the basis of (f). Smith has
correctly inferred (g), (h), and (i) from a proposition for which be has
strong evidence. Smith is therefore completely justified in believing each
of these three propositions, Smith, of course, has no idea where Brown is.
But
imagine now that two further conditions hold. First Jones does not
own a Ford, but is at present driving a rented car. And secondly, by the
sheerest coincidence, and entirely unknown to Smith, the place mentioned
in proposition (h) happens really to be the place where Brown is. If these
two conditions hold, then Smith does not know that (h) is true,
even though (i) (h) is true, (ii) Smith does believe that
(h) is true, and (iii) Smith is justified in believing that (h) is
true. Gettier
concluded that justified, true belief is not sufficient for knowledge, but
most philosophers are inclined to think that it just means that we have a
lot more work to do in determining exactly what sort of justification is sufficient for knowledge. There’s nothing in the Gettier
example to rule out the idea that some modification of the notion
couldn’t solve that problem.
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