Epistemology Skill

Master the theory of knowledge: What is knowledge? How is belief justified? Can we know anything?

Core Questions

Question Issue Stakes

What is knowledge? Analysis Definition of knowledge

What justifies belief? Justification Epistemic norms

Can we know anything? Skepticism Scope of knowledge

What are sources of knowledge? Sources Perception, reason, testimony

The Analysis of Knowledge

Traditional Analysis

JTB: Knowledge = Justified True Belief

S knows that P iff:

1. S believes that P (belief condition)
2. P is true (truth condition)
3. S is justified in believing P (justification condition)

Gettier Problem

Gettier Cases show JTB is not sufficient:

GETTIER CASE #1 ═══════════════

Smith has strong evidence that Jones will get the job (told by company president).

Smith also knows Jones has 10 coins in his pocket.

Smith infers: "The man who will get the job has 10 coins in his pocket."

Unknown to Smith: HE (Smith) will get the job. And Smith happens to have 10 coins in his pocket.

Smith's belief is: ✓ Justified (by evidence about Jones) ✓ True (Smith will get job, has 10 coins) ✗ NOT knowledge (too lucky!)

Post-Gettier Theories

Fourth Condition Approaches:

• No false lemmas

• Causal connection

• Defeasibility (no truths that would defeat justification)

Tracking (Nozick):

• S knows P iff: If P were false, S wouldn't believe P

• Sensitivity condition

Safety (Sosa, Pritchard):

• S knows P iff: S couldn't easily have been wrong

• In nearby possible worlds where S believes P, P is true

Virtue Epistemology:

• Knowledge = true belief from intellectual virtue

• Success attributable to cognitive ability

Theories of Justification

Foundationalism

FOUNDATIONALIST STRUCTURE ═════════════════════════

DERIVED BELIEFS ├── Justified by inference ├── From more basic beliefs └── Not self-justifying

     ↑
     │
BASIC BELIEFS
├── Self-justifying
├── Need no support from other beliefs
└── Foundation of knowledge

Basic Beliefs:

• Classical: self-evident, incorrigible

• Modest: defeasibly justified without inference

Coherentism

COHERENTIST STRUCTURE ═════════════════════

┌─────────────────────┐
│                     │

┌───▼───┐ ┌─────┴───┐ │ Belief ├──────────►│ Belief │ │ A │◄──────────┤ B │ └───┬────┘ └────┬───┘ │ │ │ ┌─────────┐ │ └────► Belief ◄──────┘ │ C │ └────────┘

No foundations; mutual support

Objection: Coherent fiction could be well-justified but false (isolation problem)

Infinitism

• No basic beliefs

• No circular justification

• Infinite regress is not vicious

• We can always provide further reasons

Internalism vs. Externalism

Internalism Externalism

Justifiers must be accessible to subject Justifiers may be external

What I can know by reflection Reliable processes suffice

Epistemic responsibility Connection to truth matters

Examples: evidentialism Examples: reliabilism

Skepticism

Cartesian Skepticism

SKEPTICAL ARGUMENT ══════════════════

1. I cannot know I'm not a brain in a vat (BIV)
2. If I know I have hands, I can deduce I'm not a BIV
3. If I can't know the conclusion, I can't know the premise
4. Therefore, I don't know I have hands

CLOSURE PRINCIPLE: If S knows P, and S knows P→Q, then S can know Q

Responses to Skepticism

Moorean Shift:

• I know I have hands

• If I have hands, I'm not a BIV

• Therefore, I know I'm not a BIV

• Common sense trumps skeptical premises

Contextualism:

• "Know" has different standards in different contexts

• In everyday contexts, we do know

• In philosophical contexts, standards are higher

• Both claims are true (in their contexts)

Relevant Alternatives:

• Knowledge requires ruling out relevant alternatives

• BIV is not a relevant alternative in normal contexts

Sources of Knowledge

Perception

Direct Realism: We perceive external objects directly Indirect Realism: We perceive sense-data caused by objects Idealism: Objects are mind-dependent

Problems:

• Perceptual error, illusion

• Skepticism about external world

• Theory-ladenness of observation

Reason (A Priori Knowledge)

Rationalism: Some knowledge is innate or a priori Examples: Mathematics, logic, conceptual truths

Problems:

• How do we access a priori truths?

• Are they merely analytic?

• Quine's attack on analytic/synthetic distinction

Testimony

Reductionism: Testimony reducible to other sources Anti-Reductionism: Testimony is fundamental source

Conditions: Speaker sincerity, competence, listener's critical uptake

Memory

Preservative: Memory preserves justification Generative: Memory can generate new knowledge Problems: False memories, reliability

Key Concepts

Epistemic Virtues

Virtue Description

Intellectual humility Recognizing limits

Open-mindedness Considering alternatives

Intellectual courage Pursuing truth despite cost

Thoroughness Careful investigation

Fair-mindedness Impartial assessment

Evidence

Evidentialism: Justification proportional to evidence Evidence types: Perceptual, testimonial, inferential

Degrees of Belief (Bayesian)

• Credences: Degrees of belief (0-1)

• Conditionalization: Update on evidence

• Bayes' theorem: P(H|E) = P(E|H)·P(H)/P(E)

Key Vocabulary

Term Meaning

Justified Having good reasons

A priori Independent of experience

A posteriori Dependent on experience

Analytic True by meaning

Synthetic True by world

Infallible Cannot be wrong

Defeasible Can be overridden

Propositional knowledge Knowledge that P

Knowledge how Practical knowledge

Epistemic luck Being right by chance

Closure Knowledge closed under known entailment

Integration with Repository

Related Themes

• thoughts/knowledge/ : Epistemological explorations

• thoughts/consciousness/ : Perception, self-knowledge