TRIPARTITE VIEW
Propositional knowledge is defined as justified true belief – S knows P if and only if:
1. S is justified in believing that P.
2. P is true.
3. S believes that P.
These conditions are jointly sufficient and individually necessary for knowledge.
Necessary and A necessary condition is something you need in order to have the thing in question e.g. water is a
sufficient conditions: necessary condition of rain, you cannot have rain without water.
However, water in and of itself is not enough to guarantee rain as there are other conditions which
need to be met, such as the water must be falling from the sky. Water is a necessary but not
sufficient condition of rain.
Sufficient conditions, when met, guarantee the existence of the thing in question e.g. being an uncle
is a sufficient condition for having relatives. Unclehood guarantees, but is not a necessary condition,
for having relatives, as it is possible for a person not to be an uncle but to have relatives.
Some conditions can be both necessary and jointly sufficient e.g. being both unmarried, and a man
are necessary conditions for being a bachelor, but you cannot be a bachelor if both these conditions
are not met.
The tripartite view states that belief, truth, and justification are necessary and jointly sufficient
conditions for knowledge.
Issue: the conditions Justification: Imagine a friend guesses a dice will land on 6 and it does – we are reluctant to say she
are not individually knew this because a true belief is not enough, and valid justification is needed i.e. it was a loaded
necessary dice. However, some people believe things without knowing why they believe it. Chicken sexing is a
case – some people can reliably sort male and female chicks. They can do this quickly and efficiently
and are almost always right. But chicken sexers cannot tell you how they are doing what they are
doing. A female chick just feels differently, but they cannot give any kind of verbal ustification beyond
this. So let us say that Brian, the chicken sexer, says that a chick is female. He is correct, so the truth
condition is in place. Brian also believes that the chick is female, so the belief condition is in place.
But is he justified? Many people think that the chicken sexers have no real justification, so is Brian’s
true belief knowledge? If he almost always right, then, it is hard to deny that this is knowledge and
yet there does not seem to be justification.
Truth: Everyone knew that stress caused ulcers before two Australian doctors in the early 80s proved
that ulcers are actually caused by bacterial infection. Hazlett is trying to show that ‘know’ is not a
factive verb (one that implies a truth). We often use the verb ‘know’ in this way. On finding out that
the favourite in a tennis match has been beaten we might say, ‘I thought I knew he was going to win
but he didn’t’.
Belief: Some dispute whether belief is necessary for knowledge as it may be possible to know that P,
without believing that P. It may seem incoherent to state that one knows that P, but does not believe
that P, this stems from the belief that it is a necessary condition to be honestly asserting this. No one
would assert that they know it is raining, but don't believe it is raining. However, some people equate
knowledge more with successful action – e.g. you may hesitantly get the answer right on a quiz
(having been ta ught this answer but you cannot remember it), so in this case, you knew it, even
though you did not truly believe you did. Knowledge and belief are different mental states, as
knowledge is infallible, but beliefs can be fallible, so knowledge must involve going beyond belief.
Issue: the conditions Gettier Problem 1:
are not sufficient – 1. Smith and Jones interviewing for same job.
Gettier problems 2. Smith hears interviewer say “I’m going to give Jones the job”.
(JTB that isn’t 3. Smith sees Jones put 10 coins in his pocket.
knowledge it’s just 4. Smith forms the belief “the man who gets the job has 10 coins in his pocket”.
lucky) 5. Smith ends up getting the job instead.
6. Smith also has 10 coins in his pocket.
Smith’s belief meets JTB conditions – justified as he hears the interviewer and sees Jones with the
coins, belief as he formed that belief., and true because the man who got the job had 10 coins in his
pocket. BUT, yes it’s a JTB but seems wrong to say it’s knowledge because it was just luck that led him
to being right. He thought Jones would get the job, and it is just a coincidence that Smith has 10 coins
– therefore JTB is not sufficient for knowledge here.
Gettier Problem 2:
1. Smith has a justified belief that “Jones owns a Ford”.
