AS Philosophy - Theory of Knowledge - Unit 4: Knowledge, Belief and Truth

AS Philosophy - Theory of Knowledge - Unit 4: Knowledge, Belief and Truth

AS Philosophy

Module 1

The

Theory

Of

Knowledge

Unit 5

Knowledge, Belief and Truth

“What is Truth? Said jesting Pilate, and would not stay for an answer.”

Of Truth, Essays or Counsels Civil and Moral, Francis Bacon.

Definitions of Truth

In the gospel of John in the New Testament (18:28-40), Jesus is brought up before Pontius Pilate, the Roman governor of the region. Pilate, a practical and worldly man, is bemused as to why Jesus has been brought before him: what has he done?

During a brief exchange between Pilate and Jesus, we see two distinct concepts of truth at work. On the one hand, Jesus has a very firm idea (18:37):

“You are right in saying I am a king. For this reason I was born, and for this I came into the world, to testify to the truth. Everyone on the side of truth listens to me.

To which Pilate merely replies: “What is truth?” – as if to say, “You think truth exists independently of everyone as a standard by which we can judge our beliefs?”

This sort of debate has been central to philosophy for centuries. We will now look at different theories of knowledge, truth and belief.

What is Knowledge?

There are a number of different ways in which the verb ‘to know’ is used. I can know someone’s voice, a piece of music or my own mind. However, this sort of knowledge seems less specific than factual knowledge: I can know someone’s voice or face without necessarily being able to put a name to it; I may change my mind.

Factual knowledge usually entails knowing that something is the case. It is also called propositional knowledge because it can take the form of a logical proposition. For example, “Wales’ rugby team is not as good as it once was” proposes a fact. It is something which might either be true or false.

Knowledge by Description and Acquaintance

Bertrand Russell identified two main types of knowledge: knowledge by description and knowledge by acquaintance. The second of these we might also call "propositional knowledge". In other words, I know that something is true (or false). These sorts of statement can therefore always be phrased in the following way: "I know that X is true" (where X is a statement such as "John is bald").

The other type of knowledge is different in the sense that it cannot be put into the same sort of form. For instance, if I say, "I am in pain", it is not the same as knowing some sort of detailed medical account of your pain. Similarly, saying "I know how to ride a bike" is not the same as saying, "I know that to ride a bike you need to push the pedals round and turn the handle bars". The distinction here is between being acquainted with direct sense experience (pain, balance and co-ordination, a friend’s face) and inference (“I know the chemical composition of citric acid”).

Exercise

Which of these two different types of knowledge – if either – do you feel are less certain? Does the fact that many statements which claim knowledge by acquaintance cannot be completely translated into knowledge by description make them less or more certain?

Knowledge and Belief

Although sometimes the words ‘know’ and ‘believe’ are used interchangeably, in a strict sense they are very different. Probably, no one would criticise you for saying, “I believe it’s time for us to go” when you actually mean simply, “It’s time for us to go”.

However, belief frequently implies that there is something you are either unsure of or for which there is insufficient proof. For instance, I might say, “I believe that a European single currency is a good thing”, or “I believe that Wales will win next Saturday”. These things may very well be false: the single currency may prove disastrous, and Wales – judging on recent form – may very well lose.

Knowledge, on the other hand, in its strict sense, only applies to things that are true. Therefore, it may be inappropriate to say, “I know that Wales will win” or that “I know which horse will win the 3:30 at Kempton”, because there is an element of doubt involved (unless I have some proven psychic ability, such as Mystic Meg).

Exercise

Try to think of a sentence which meets one of these three categories (belief, knowledge by acquaintance or knowledge by description) then write it down in the first column of the box below, labelling the type of knowledge it represents in the next column (go for 2 or 3 examples of each type).

I have put in a few examples of my own to start you off.

Sentence

/

Type of Knowledge

I am in pain.

/

Acquaintance

Paris is the capital of France.

/

Description

Wales will win the Triple Crown this year. /

Belief

Conditions of Knowledge

The first philosopher to define knowledge was Plato, who stated that for us to say that we know something:

1. It must be true.
2. We must actually believe it (it must be consciously held).
3. There must be sufficient evidence for it (it must be justified).

Therefore, we may say that knowledge is ‘true justified belief’.

Exercise

Using the following table, think of things that fit these criteria in different ways (true but not justified belief, untrue but justified, etc.). Place a tick under the appropriate column heading as you go.

Statement / True? / Justified? / Believed?

How does this tripartite (3-part) definition of knowledge hold up? Have you identified any problems with it? Before going further we need to look at some useful terms.

If and only if

Like our use of the words ‘knowledge’ and ‘ belief’, the word ‘if’ has different uses. Sometimes when we use it we only want to convey a loose connection between statements: “I will come with you to the pictures if you go on Friday”. In this example, the two statements – your going to the cinema, my coming with you – are not absolutely connected. I may go to the cinema with you on another evening if you suggest it – in other words, other things are possible.

However, if I say, “I will come with you to the pictures if, and only if, you go on Friday”, I am excluding other possibilities (such as going on Tuesday). This distinction is important for philosophers because it allows them to be more precise about the relationship between certain statements.

Exercise

Indicate which of the following are examples of ‘if’ and which are examples of ‘if and only if’.

Statement

/ If / If and Only If
I will die if I stop breathing
I can make a hot cup of tea if I have hot water
I will pass my exams if there is a miracle
If I eat any more I will be sick

Necessary and Sufficient Conditions

When we talk of something being true ‘if and only if’ something else is true, this can happen in one of two ways. For instance, if we take the example, “I will grow up to be strong and healthy if I exercise and eat sensibly”, in what way might this be true? Will I be strong and healthy only from eating sensibly and exercising? Or can these things be achieved in other ways?

So, in this example:

1. These would be necessary conditions for health if it could not be achieved without them.

1. These would be sufficient conditions for health if that were all that were needed to be done in order to be healthy.

Another example might be learning to drive. Passing my theory test is a necessary condition of getting a driving license, but it is not a sufficient condition (you also need to pass your practical test).

Exercise

Take the following situations and list both necessary and sufficient conditions for something to be the case in each of them. The first example is given for you.

Situation / Necessary Condition / Sufficient Condition
Learning a foreign language / Having a source of vocabulary (foreign language speaker or dictionary) / Learning vocabulary and applying it using correct grammar
Riding a bike
Meeting a friend for a drink
Getting up in the morning at 7am
Making a cake

Gettier Problems

In 1963, the philosopher Edmund Gettier published an article in the Journal Analysis called “Is Justified True Belief Knowledge?” The article, although quite short, had a profound effect on epistemology by challenging the long-held traditional definition of knowledge as proposed by Plato almost two and a half thousand years before.

Gettier’s objections go something like this. Imagine a situation where all the traditional conditions for knowledge were fulfilled – and yet you could not say that it constituted knowledge. For instance, take the following situation:

1. Fred believes that Sam is in his room;
2. Fred sees Sam in his room;
3. Sam is in his room.

This fulfils the traditional conditions of knowledge. Sam is in his room, Fred believes that he is and is justified in doing so by the experience of seeing him there. However, unknown to Fred, what he sees in Sam’s room is not Sam at all, but his twin brother Tim. However, Sam is actually in the room but is just out of sight (e.g. he is hiding under the bed).

From this point of view, it would appear that Fred is right, but only by coincidence. Sam is in the room (albeit under the bed), Fred is justified in believing he is, except that it cannot be said to be a genuine case for knowledge because Fred is only correct through coincidence. Does this mean that the tripartite definition of knowledge is incorrect?

Exercise

Can you think of any other situations in ordinary life where it might be said that the tripartite conditions of knowledge were met, and yet you would not say that someone actually had knowledge? Try to list 3 examples.

Responses to Gettier

There have been 5 main attempts at trying to repair the damage made to the tripartite theory by introducing another condition to the triangle (making it a square). These are as follows:

1. No False Belief Condition: Beliefs cannot be based on a false belief. This attempt argues that no knowledge can be claimed if it relies on a false belief. So, in our example, it is false that Fred is actually looking at Sam.

1. Defeasibility Condition: Something is known as long as there is no evidence to the contrary. This is a common sense view, argued by Keith Lehrer and Thomas D. Paxson, which argues that Fred would be perfectly entitled to claim that he knows that Sam is in the room because he is not aware of anything to the contrary. In other words, there is nothing to "defeat" the claim - "defeasibility" meaning "capable of being defeated". Another example would be the flat earth theory, or the concept that the earth was the centre of the universe. These were once claimed as knowledge by the majority of people – until further knowledge arrived to prove that a different case is true.

1. Reliability. This theory proposes that justified true belief should be obtained through a reliable method. Therefore, if I believe that Sam is in the room but I am also aware that my method of checking is not wholly reliable (or that I am aware that there are more reliable methods), then I cannot claim knowledge in this instance.

1. Conclusive Reasons Condition: A reason must exist for the belief that would not be true if the belief itself were false. This was first put forward by Fred Dretske. If, for example, I believe that there is a chair in front of me, the reason for believing that it is there would not exist if the belief were false (that is, if the chair were not there).

1. Causal Connection Condition: There must be a causal connection between the knowledge and the belief. This argument, first put forward by Alvin Goldman, states that a belief must have an appropriate connection to the knowledge claimed. In our example, Fred should not be able to claim that he knows Sam is in the room because there is no ‘appropriate connection’ between his viewing Tim (Sam’s twin brother) and his conclusion that Sam is in the room.

Exercise

Are there any problems with any of the above theories? Take each in turn and see if you can think of how they might be criticised.

Analysis of the Responses

Each of the 5 different responses admits that Gettier has highlighted a problem, and each seeks to resolve it by adding another condition to knowledge. So, what was a tripartite division becomes a four –part one. You could also think of this as moving from a triangle to a square.

Let's now look at each of the responses in turn:

1. No False Belief Condition. This response argues that we cannot be said to know anything if it is based on a false belief or on a group of beliefs of which one is false. So, in the example we have been considering, I cannot be said to know that Sam is in the room because my "knowledge" is based on the false belief that I am seeing Sam (whereas I am actually seeing Tim). So, adding this as an extra condition seems to work, doesn't it?

The main problem with this theory is that it seems to deny things that we would say that we know. For instance, I may claim to know a certain piece of information because my friend Bob told me. However, I might also believe that Bob is trustworthy because he has never lied to me - which may turn out to be false. In this way, although Bob is not lying in this instance, my belief that Bob has never lied to me is false. However, is this really a reason not to say that we don't really know that what Bob has said is true? In this case the rule seems too harsh. What if I had other information that agreed with what Bob said (so that I have other evidence for the truth of the statement)? According to this theory, my false belief that Bob has never lied to me means that I cannot claim that I know this piece of information.