Epistemology: The Definition of Knowledge

What are the origins of the Tripartite Definition?

Plato argues that knowledge is ‘true belief accompanied by a rational account,’ simplified to ‘Justified true belief’

How does the Tripartite Definition define knowledge?

By providing necessary and sufficient conditions

Exemplify the use of necessity and sufficiency in the Tripartite Definition defining knowledge

You can’t know something if it isn’t true, you can’t you can’t know something you don’t believe, something unjustified is something you don’t know, e.g. ‘Pluto has five moons because five is my lucky number’

What is a Gettier Case?

A justified true belief that is not knowledge, but is derived from luck

What is Gettier Case 1?

• Smith and Jones are interviewing for the same job

• Smith hears the interviewer say, “I’m going to give Jones the job”

• Smith also sees Jones count 10 coins from his pocket

• Smith thus forms the belief that “the man who will get the job has 10 coins in his pocket”

• But Smith gets the job, not Jones

• Then Smith looks in his pocket and, by coincidence, he also has 10 coins in his pocket

What is disjunction introduction?

Adding ‘or some other statement’ on the end of a true statement; the full statement will still be true

What is Gettier Case 2?

• Smith has a justified belief that “Jones owns a Ford”

• So, using the principe of disjunctive introduction above, Smith can form the further justified belief that “Either Jones owns a Ford or Brown is in Barcelona”

• Smith thinks his belief that “Either Jones owns a Ford or Brown is in Barcelona” is true because the first condition is true (i.e. that Jones owns a Ford)

• But it turns out that Jones does not own a Ford

• However, by sheer coincidence, Brown is in Barcelona

In what way are the Tripartite Definition conditions not necessary?

• J: Children and animals have knowledge, but can’t justify it

• T: Zagzebski’s definition of knowledge does not include true as a condition, but talks about acts of intellectual virtue

• B: There are some scenarios in which someone knows something but doesn’t believe it, such as getting a factual question right without believing it to be so, as you may be unsure of the answer. E.g. You heard many years ago that Pluto has 5 moons but forgot it consciously; when asked years later, you say 5, even though you’re not sure and don’t really believe it

What is JTB + No False Lemmas?

James has knowledge of P if:

P is true

James believes that P

James’ belief is justified

James did not infer P from anything false

How does JTB + No False Lemmas avoid the problems of the Gettier cases?

The belief ‘the man who will get the job has 10 coins in his pocket’ is inferred from the false lemma, ‘Jones will get the job’

How does Fake Barn County make No False Lemmas problematic?

The belief is true

It is justified by his visual perception of the barn

It is not inferred from anything false

What is Fake Barn County?

In Fake Barn County, the locals create fake barns that look like real barns

Henry does not know this

Henry often thinks that he is looking at a barn when they are false

These beliefs are not knowledge, because they are not true

However, Henry forms this belief when he looks at a real barn

What is reliabilism?

James knows that P if

P is true

James believes that P

James’ belief that P is caused by a reliable method

What is an advantage and disadvantage of reliabilism?

It can be attributed to animals and children that have knowledge

Fake Barn County relies on visual perception, which is reliable, when seeing a fake barn

What is infallibilism?

A belief’s justification must be certain

What is the problem with infallibilism?

Too damn strict, everything basically is not knowledge

What is Zagzebski’s formula for constructing Gettier cases to defeat definitions of knowledge that are (e.g.) true belief + some third condition?

• Start with a situation where there is a belief that fits the definition (‘true belief + some third condition’) but is false due to bad luck

  • E.g. Henry’s belief “there’s a barn” when he is looking at the fake barns

• Then change the situation to one where the belief fits that definition (‘true belief + some third condition’) but is true due to good luck

  • E.g. Henry’s belief “there’s a barn” when he is looking at the one real barn

• In the second case, the belief will still fit the definition (‘true belief + some third condition’) because it’s basically the same as the first case

• But the second case won’t be knowledge, because it’s only true due to luck

What is Zagzebski’s definition of knowledge?

James knows that P if:

James believes that P

James’ belief that P arises from an act of intellectual virtue

What is intellectual virtue in Zagzebski’s definition of knowledge?

You must have the correct motivation (you want to find the truth) and you succeed as a result of that virtue

What is Sosa’s virtue epistemology?

	Archery	Knowledge
Accuracy	The arrow hits the target.	The belief is true.
Adroitness	The archer is skilled.	The believer is intellectually virtuous.
Aptness	The arrow hits the target because of the archer’s skill, not just luck.	The belief is true because of the believer’s intellectual virtues.

What is the problem with Virtue Epistemology?

If this is true, can children and animals still have knowledge?