Philosophy of Science Skill

Master the philosophical foundations of science: What is scientific method? What is explanation? Are scientific theories true?

Core Questions

Question Issue

What distinguishes science from non-science? Demarcation

How do we confirm theories? Confirmation

What is scientific explanation? Explanation

Are theories true or useful fictions? Realism

How does science change? Theory change

Scientific Method

The Problem of Induction

Hume's Problem: How do we justify inductive inference?

• Past regularities don't logically guarantee future ones

• Cannot use induction to justify induction (circular)

• Yet science relies on induction

Falsificationism (Popper)

POPPER'S FALSIFICATIONISM ═════════════════════════

DEMARCATION CRITERION ├── Science: Falsifiable claims ├── Pseudo-science: Unfalsifiable └── Examples: Astrology, Freud (unfalsifiable)

METHOD ├── Bold conjectures ├── Severe tests ├── Refutation → new conjecture └── Corroboration ≠ confirmation

KEY IDEA: We never confirm theories We only fail to falsify them Asymmetry: One counterexample refutes

Problems:

• Theories rarely abandoned on single refutation

• Auxiliary hypotheses can absorb refutation

• No purely observational test

Paradigms (Kuhn)

KUHN'S STRUCTURE OF SCIENTIFIC REVOLUTIONS ══════════════════════════════════════════

NORMAL SCIENCE ├── Work within paradigm ├── Puzzle-solving ├── Anomalies accumulate └── Paradigm defines problems, methods

CRISIS ├── Too many anomalies ├── Alternative paradigms emerge ├── Debate between paradigms └── Incommensurability

SCIENTIFIC REVOLUTION ├── Paradigm shift ├── Not cumulative progress ├── New worldview └── Gestalt switch

EXAMPLES: ├── Ptolemy → Copernicus ├── Newton → Einstein └── Phlogiston → Oxygen

Scientific Explanation

Deductive-Nomological (D-N) Model

D-N MODEL (Hempel) ══════════════════

EXPLANATION STRUCTURE: L₁, L₂, ... Lₙ (Laws) C₁, C₂, ... Cₙ (Conditions) ───────────────── E (Explanandum)

REQUIREMENTS: ├── Deductively valid ├── Laws are essential ├── Empirically testable └── True premises

EXAMPLE: All metals expand when heated. This is metal. This was heated. ∴ This expanded.

Problems:

• Symmetry problem (flagpole and shadow)

• Irrelevance problem

• Statistical explanation

Causal-Mechanical Model

• Explanation = tracing causal mechanism

• Not just subsumption under laws

• Mechanisms explain, not just correlate

Unificationism

• Explanation = unifying diverse phenomena

• Fewer patterns explaining more

• Newton unified celestial and terrestrial motion

Scientific Realism

The Debate

Scientific Realism:

• Mature scientific theories are approximately true

• Theoretical entities (electrons, genes) exist

• Science aims at truth

Anti-Realism (Instrumentalism):

• Theories are useful tools

• Theoretical terms don't refer

• Science aims at empirical adequacy

Arguments for Realism

No Miracles Argument:

• Science's success would be miraculous if theories weren't true

• Best explanation of predictive success is truth

• "The only philosophy that doesn't make science a miracle"

Arguments Against Realism

Pessimistic Meta-Induction:

• Past "successful" theories were false

• Caloric, phlogiston, ether

• Current theories probably also false

Underdetermination:

• Multiple theories compatible with same evidence

• Evidence doesn't uniquely determine theory

• Why think ours is true?

Structural Realism

Epistemic: We can know structure, not nature Ontic: Structure is all there is

Reduction and Emergence

Reductionism

• Higher-level sciences reducible to lower

• Biology → Chemistry → Physics

• Unity of science thesis

Emergence

• Some properties not reducible

• Whole greater than parts

• Consciousness? Life?

Multiple Realizability

• Same higher-level state, different lower-level realizations

• Pain in humans ≠ pain in octopi (neurally)

• Blocks type-identity reduction

Key Debates

Demarcation

• What makes something science?

• Falsifiability? Paradigms? Method?

• Is demarcation possible?

Theory Choice

• Empirical adequacy

• Simplicity, parsimony

• Explanatory power

• Fruitfulness

Values in Science

• Value-free ideal achievable?

• Social influences on science

• Science studies, feminist philosophy of science

Key Vocabulary

Term Meaning

Falsification Disproving through counterevidence

Paradigm Shared framework for research

Incommensurability Paradigms can't be compared

Confirmation Evidence supporting theory

Underdetermination Evidence doesn't determine theory

Instrumentalism Theories are tools, not truths

Reduction Higher explained by lower

Emergence Irreducible higher-level properties

Demarcation Distinguishing science from non-science

Corroboration Surviving falsification attempts

Integration with Repository

Related Themes

• thoughts/knowledge/ : Scientific knowledge

• thoughts/consciousness/ : Neuroscience methodology