Epistemology - Definitions of Knowledge

A priori

“Before Experience”. Something that is known “A priori” is known through reasoning, rather than senses

A posteriori

“After experience”. Something that is known “A posteriori” is known through experience by the senses

Analytic

A statement that is “Analytic” is one that is shown to be true when the terms in the sentence are examined. Ex: A circle is round is an analytic statement as to say a circle is not round would be contradictory to the definition of a circle. Analytic statements are tautological and do not rely on experience (A priori). 

Synthetic

Synthetic statements are statements that cannot be shown to be true when the terms in the statement are examined. Ex: That circle is green is a synthetic statement as to say that a circle is not green is not contradictory to the definition of a circle. Synthetic statements are tautological and rely on experience 

Tautological

If a statement is tautological, it means the predicate does not add any new information to the subject. Ex: “A circle (subject) is a round shape (predicate)” is tautological as a circle is already defined as a round shape, so no new information is added by the predicate. 

Deduction

Deduction is a type of reasoning used in deductive arguments. Deductive arguments are A priori, and use premises (propositional statements) that lead to a logical conclusion. If the premises of a deductive argument are true, then the conclusion must be true. Commonly, deductive arguments start with a universal premise, then apply the premise to something specific in order to reach a sound conclusion. Ex: All trees have a trunk (universal premise) → This is a tree (specific premise) → Therefore, this must have a trunk (conclusion)

Induction

Induction is a type of reasoning used in inductive arguments. Inductive arguments are A posteriori, and use examples (propositional statements) that lead to a logical conclusion when generalised. Even if the premises of an inductive argument are true, the conclusion may be false. Commonly, inductive arguments start with a series of universal premises, then generalise these premises in order to reach a sound conclusion. Ex: The sun rose today (premise) + The sun rose yesterday (premise) + The sun rose the day before (premise) + … → The sun will rise tomorrow (Conclusion). The more examples used, the stronger the argument 

Necessary Truth

A necessary truth is a truth that is true in all possible worlds, and cannot be true otherwise. For example: “2 + 2 = 4” is a necessary truth, meaning it must be true in all possible worlds, including dreams. The opposite of a necessary truth is not logically possible, and can never occur. 

Contingent

A contingent truth is one where the opposite is possible and it can be otherwise. For example: “The grass is green” is a contingent truth as, although the grass may be green now, it could turn brown in the summer. Contingent truths are not true in all possible worlds, such as alternate realities where grass is purple.

Valid / Invalid

An argument is valid if the conclusion logically follows on from the premises, even if neither the conclusion nor the premises are correct. For example: “ I am a tree (premise) + Trees do not respire (premise) → I do not respire (conclusion)” is a valid argument, despite the fact that neither my premises nor my conclusion are correct, because the conclusion follows logically. An invalid argument is one where the conclusion does not follow logically from the premises, even if the premises and the conclusion are true. For example: “I am a human (premise) + I am over 5’11 (premise) → My name is not John (conclusion)” is an invalid argument, as even though the premises and the conclusion were all true, the conclusion did not follow logically

Sound / Unsound

For an argument to be sound it must have premises that are true, a true conclusion, and the conclusion must follow logically from the premises (it must be valid). For example: “Person 1 is taller than Person 2 (premise) + Person 2 is taller than Person 3 (premise) → Person 1 is taller than Person 3 (conclusion)” is a sound argument as it fits the above requirements. An unsound argument is any argument which does not meet the above conditions. 

Necessary Condition

A condition is necessary if it must be present for something to be possible. For example: Truth is a necessary condition for knowledge as you cannot know something that is false

Sufficient

A condition (or several) are sufficient if, when all of them are present, a complete definition can be formed. For example, according to JTB theory: Justification, Truth, and Belief are sufficient conditions to define knowledge

3 Types of knowledge

Ability knowledge : Knowing HOW (I know how to tie my shoelaces)

Acquaintance knowledge : Knowing OF (I know Dave)

Propositional knowledge : Knowing THAT (I know that Lima is the current capital of Peru), requires belief and can be explained using language (the others cannot)

Tripartite definition of Knowledge

Requires:

• Justification : Either by valid evidence (textbooks / trustworthy news sources etc …) or first person testimony without caveats (decent weather / good eyesight etc …)

• Truth : The thing you claim to know must be true

• Belief : You must believe that you know it 

The 3 conditions are individually necessary (all are required for knowledge) and (supposed to be) jointly sufficient (when combined they form a complete definition) 

2 Types of definitions: (According to Zagzebski)

1. Definitions based on essence: A strawberry is a red, conic shaped fruit with seeds

2. Definitions not based on essence: Strawberries are very tasty

Proposition

A statement about what someone believes is true, contains a subject and a predicate.

Assertion

A statement that has a truth value (True, False, or Indeterminate), even if the truth value is currently unknown 

Truth value

The state of being true, false or indeterminate 

Propositional attitude

A speakers mental state towards their proposition. Either a propositional attitude of belief (speaker believes it is true), or a propositional attitude of disbelief (speaker believes it is false)

Gettier case

A case where a person believes a proposition (P), P is true, and they have justification for believing P, but we do not say they know P because P only happens to be true due to luck. Counteracts Tripartite definition of knowledge. (You know the examples ong)

Zagzebski’s view on defining knowledge:

• Knowledge doesn’t have an essence as the idea of what knowledge is has changed over time, so it can’t be defined 

• However, Zagzebski argues we should still attempt to define knowledge by examining its components 

• We could also try and define knowledge by looking at what causes it (Causal definition)

4 Types of invalid definitions:

• Circular definitions : “Knowledge is to know something”

• Obscure definitions : “Water is Dihydrogen monoxide” (True but too complicated)

• Negative definitions : “Dogs are not cats” 

• Ad hoc definitions : “A bird is a creature that can fly” (Created to address a specific problem)

Differences between real and nominal essence:

Real essence: 

• Can be defined by it’s properties 

• Can have a fixed definition 

• Ex: Water

Nominal essence: 

• Can’t be defined by it’s properties

• Can’t have a fixed definition

• Ex: Weeds 

Times when it can be argued the 3 JTB conditions are not individually necessary

• No belief (COLIN RADFORD): A man takes a history test years after he leaves school, so he believes he has forgotten everything. He is unsure of his answers but gets 100%, so it can be argued that even without believing he knows the answers, he actually has the knowledge. 

• Belief and knowledge are separate (TIMOTHY WILLIAMSON): It can be argued that knowledge is separate from belief as you don’t know something by believing it. For example, using perception: We can only perceive things if they are really there, if they are hallucinating then we are experiencing an entirely different mental state to perception, even if we believe that it is there. The same applies to knowledge, as we can believe things even if they are false, but knowledge involves no other possibilities, so the two are different.

• No truth (THOMAS KUHN): Science involves large shifts in thought, called “paradigm shifts”. We cannot compare 2 paradigms in a way to call them true and false because there is not a ‘right’ set of concepts that matches reality. So if we insist that knowledge must involve truth, it becomes impossible to talk of scientific knowledge

• No justification (CRISPIN SARTWELL): People vote for a political party without any justification because they ‘just know’ that they are making the right choice

What is the NFL definition of knowledge:

You can say you know P if:

1. You believe that P

2. P is true

3. You have justification for believing P 

4. You did not infer P from anything false

How can NFL solve a Gettier case?

NFL can solve the S+J Job Gettier case as S’s conclusion “The person who has ten coins in their pocket will get the job” was based of the false assumption that “J would get the job”, so since the boss was wrong and J does not get the job, the proposition “J will get the job” is a false lemma, so S does not know “The person who has 10 coins in their pocket will get the job” 

What is the fake barn style counterexample?

1. S is driving through a county, called “Fake barn county”, which is full of fake barns

2. S occasionally looks up and thinks to themselves “That is a real barn” (P)

3. S is incorrect as P is false (the barns are fake)

4. However, on one occasion, S sees a barn and thinks P

5. P is true this time, as the barn is the only real barn in the whole county 

6. S believes P, is justified in believing P, and P is true. But we would not say that S knows P, as it happened by luck (S happened to look up at the only real barn in the county, which is exceedingly unlikely)

How does the fake barn style counterexample defeat NFL:

According to NFL, S’s belief that P (“That is a real barn”) is knowledge, however S’s belief is clearly not knowledge, as it is evident they just got lucky

What is the definition of knowledge according to reliabilism?

You know P if:

1. You believe that P 

2. P is true

3. Your belief that P is formed by a reliable process (a reliable method is one that produces a high percentage of true beliefs)

What is the main advantage of reliabilism?

It allows for children and animals to have knowledge, as they can use reliable processes

How does the fake barn style counterexample defeat reliabilism:

S’s belief that P (“That is a real barn”) is formed by a reliable process (visual perception). Therefore according to reliabilism, S does know P, however S’s belief is clearly not knowledge, as it is evident they just got lucky

How can reliablism be strengthened? 

1. Nozick’s adds the sensitivity condition: “If P were false, S would not believe that P”. For example: Imagine Smith had 12 coins instead of 10 and the Gettier case no longer works, so therefore it doesn’t count as knowledge 

2. Redefinition to include the fact that making an inference from a false belief is not a reliable process 

3. No relevant alternatives: Goldman suggested we should only count a process if that process is able to distinguish between the truth and other relevant possibilities. For example, in the fake barn counterexample, it is presumed that S is not an expert in barns, and so would be unable to differentiate a fake barn from a real one, meaning it could not count as knowledge. 

What is Zagzebski’s definition of knowledge?

You know P if:

1. You believe that P

2. Your belief arose from an act of intellectual virtue (Truth is implicit as intellectual virtues enable to reach true conclusions reliably)

Zagzebski argues that we think of knowledge as good as it helps us to satisfy our needs and desires

What is an intellectual virtue?

According to Zagzebski, a virtue has 2 components: 

1. A virtue must motivate us to pursue what is good

2. A virtue involves a component that enables us to be successful in our pursuit, so that we can form true beliefs 

What is Sosa’s analogy to explain knowledge?

Sosa argues that knowledge has 3 parts, relating it to an archer firing at a target:

1. Accuracy: The belief is true (the archer hits the target)

2. Adroitness: The believer is intellectually virtuous (The archer is skilled)

3. Aptness: The belief is true because of the believers intellectual virtues (The arrow hits the target because the archer is skilled)

According to Sosa, for something to qualify as knowledge the belief must be true as a direct consequence of the believer exercising their intellectual virtues (it must be apt). This distinguishes Sosa’s understanding of knowledge from those criticised by Zagzebski. 

What is a problem with virtue epistemology?

Virtue epistemology means that children or animals can not know anything, as they are incapable of using intellectual virtues to form beliefs. This appears contradictory to reality, as it seems to us that children and animals can know things, even if their knowledge is limited.

What is the definition of knowledge according to Infallibilism?

To know P, you must:

1. Believe that P

2. P is a necessary truth (P must be true, it is impossible for it to be otherwise)

What is the major problem with infallibilism: 

Infallibilism limits the amount that you can know to a very small pool of information which cannot be doubted. For example: You know that you are real due to Descartes proof (Cogito ergo sum // I think therefore I am), but most other things that we would call knowledge can be doubted, as you could be a brain in a vat, or you could be deluded by an evil demon that manipulates your mind into believing that 2+2=4, when in reality 2+2=22. This goes against the social and cultural conventions that have defined knowledge in the past, so infallibilism is not compatible with reality.