epistemology

| 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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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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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 |

---

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

---

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

---

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)

---

| 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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Related Themes

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