There are three types of knowledge: practical/ability, acquaintance, and propositional. Practical
knowledge is defined as knowing how to do something, like “I know how to drive”. Acquaintance
knowledge is defined as being familiar with something, like “I know what an apple looks like”. Then
there’s propositional knowledge, this is the one we’re focused on in philosophy, this is knowing
something factual; “I know that the moon orbits the earth.” So how do we define propositional
knowledge, in the sense that, how do we know when to call something knowledge? Linda Zagzebski
said that knowledge requires a ‘real definition’, which is a definition which captures the nature of
the essence of the term. We look at knowledge in terms of necessary and sufficient conditions,
these conditions are known as justified true belief (the JTB definition). Why do I need belief? It
seems impossible to say you know something if you don’t believe it. You also need
truth as you cannot know something that is false. Plato makes the important
distinguishment between ordinary true belief and knowledge, the difference is
justification; he uses the example of a statue to make this apparent. A statue needs a
solid foundation in order for it to stand without falling, in the same way a true belief
needs justification in order for it to stand alone as knowledge. However, there is
dispute over the JTB definition, some argue that belief isn’t necessary. Take the example of Albert;
he’s sitting a history exam, he doesn’t believe that he knows the answers to the questions, yet he
get’s all of them correct. So, he therefore has knowledge without belief, critics may argue that
Albert did believe however a stronger part of his conscience doubted his ability to answer the
questions. Truth is also said to be unnecessary, there’s been times in the past where people have
known things that aren’t true. For example, Heliocentrism, this is the belief that the sun is at the
centre of the universe. Galileo had evidence for this, Venus orbited the sun. A
response to this is paradigm shifts, this is defined as a case where this is
enough compelling evidence to render a system false. Thomas Khun argued
that this is always happening so we must redefine truth, he described it as
something hat aligns with contemporary systems. Justification is seen as the
weakest component of the JTB definition, Plato’s Road to Larissa shows the
importance of a strong justification when making a knowledgeable claim.
There are two men who want to go to Larissa, one decides to wait for a tour guide to tell him where
to go, whilst the other man goes by himself. Taking a random road, he somehow manages to end up
in Larissa. It seems evidently wrong to say the second man knows the way
to Larissa, as his justification isn’t strong. This is just epistemic luck, a
lucky guess that just so happens to be true.
Gettier is the main critic of the JTB definition, and he uses two examples
to prove that knowledge can’t simply be justified true belief; we’ll look at
‘the coin example’. Two men have just finished having a job interview and are now waiting for to
hear who gets the job. Jones begins to count the number of coins in his pocket and establishes that
he has 10 coins. Later, the manager gives some indications that Jones will get the job and Smith
concludes that the man with ten coins (Jones)will get the job. But Smith gets it, unbeknown to him
he has ten coins in his pocket as well. So, let’s break it down, how does this disprove the JTB
definition?
1 P is true (the man who will get the job has ten coins in their pocket)
2 Smith believes P is true.
3 Smith has justification for P. (Jones has 10 coins in his pocket)
However, we know that this isn’t knowledge, as he gets it wrong. In pursuit of finding a solution to
this problem we have developed four responses. Infallibilism, No False Lemmas, Reliablism and
Virtue Epistemology.