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

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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

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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

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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

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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

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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)

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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

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Integration with Repository

Related Themes

• thoughts/knowledge/: Epistemological explorations
• thoughts/consciousness/: Perception, self-knowledge