Master Early Modern philosophy from Descartes through Kant. Use for: rationalism, empiricism, the epistemological turn, mind-body problem, substance metaphysics...
Master the early modern period (c. 1600-1800)—the age of the "epistemological turn" when philosophy focused on questions of knowledge, mind, and method, culminating in Kant's critical synthesis.
Medieval Philosophy: What is real? (Metaphysics first) Modern Philosophy: What can we know? (Epistemology first)
SCIENTIFIC REVOLUTION (Background)
├── Copernicus (1473-1543): Heliocentrism
├── Galileo (1564-1642): Mathematical physics
├── Newton (1643-1727): Mechanics, calculus
└── New confidence in human reason
CONTINENTAL RATIONALISM
├── Descartes (1596-1650): Method, dualism
├── Spinoza (1632-1677): Monism, Ethics
└── Leibniz (1646-1716): Monads, pre-established harmony
BRITISH EMPIRICISM
├── Locke (1632-1704): Tabula rasa, ideas
├── Berkeley (1685-1753): Idealism
└── Hume (1711-1776): Skepticism, naturalism
SYNTHESIS
└── Kant (1724-1804): Transcendental idealism
| Thesis | Description |
|---|---|
| Innate Ideas | Some ideas are in the mind prior to experience |
| Reason as Source | Reason, not sense, provides genuine knowledge |
| Mathematical Model | Philosophy should emulate mathematical certainty |
| Substance Metaphysics | Reality consists of substances with attributes |
The Method of Doubt:
CARTESIAN DOUBT
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LEVEL 1: SENSES
├── Senses sometimes deceive (optical illusions)
├── Therefore, cannot trust senses completely
└── But this doesn't show everything from senses is false
LEVEL 2: DREAMING
├── I cannot distinguish dreaming from waking with certainty
├── Any sensory experience could be a dream
└── But even in dreams, mathematical truths hold
LEVEL 3: EVIL DEMON (Malin Génie)
├── Imagine a supremely powerful deceiver
├── Could make me wrong about everything
├── Even 2+2=4 could be implanted deception
└── Global, hyperbolic doubt
SURVIVING THE DOUBT:
"Cogito, ergo sum" — I think, therefore I am
├── Even if deceived, I must exist to be deceived
├── First certain truth
└── Foundation for rebuilding knowledge
Meditations Structure:
| Meditation | Content |
|---|---|
| I | Method of doubt |
| II | Cogito; nature of mind |
| III | Proofs of God's existence |
| IV | Truth and error |
| V | Essence of material things; ontological argument |
| VI | Real distinction of mind and body; external world |
Mind-Body Dualism:
CARTESIAN DUALISM
═════════════════
MIND (Res Cogitans) BODY (Res Extensa)
───────────────── ─────────────────
Thinking substance Extended substance
Unextended No thought
Indivisible Divisible
Free Mechanical
Known directly Known through senses
INTERACTION PROBLEM:
How can unextended mind affect extended body?
Descartes: Pineal gland (unsatisfying)
Clear and Distinct Ideas:
Radical Monism: There is only ONE substance—God/Nature (Deus sive Natura)
SPINOZISTIC METAPHYSICS
═══════════════════════
SUBSTANCE
├── That which is in itself and conceived through itself
├── There can be only ONE substance (infinite, necessary)
├── = God = Nature
└── Has infinite attributes
ATTRIBUTES
├── What intellect perceives as constituting substance
├── We know two: Thought and Extension
├── Mind and body are same thing under different attributes
└── Parallelism, not interaction
MODES
├── Modifications of substance
├── Individual minds, bodies are modes
├── Finite, dependent, determined
└── All follow necessarily from God's nature
ETHICS
├── Freedom = understanding necessity
├── Highest good: intellectual love of God
├── Emotions: adequate vs. inadequate ideas
└── "Sub specie aeternitatis"
Determinism: Everything follows necessarily from God's nature
Monads: Ultimate simple substances
LEIBNIZIAN MONADOLOGY
═════════════════════
MONADS
├── Simple substances, no parts
├── No windows (cannot be affected from outside)
├── Each contains whole universe from its perspective
├── Differ in clarity of perception
└── Hierarchy: bare → souls → spirits
PERCEPTION AND APPETITION
├── Each monad perceives entire universe
├── Most perceptions are "petites perceptions" (unconscious)
├── Appetition: internal drive from perception to perception
└── Mirrors the universe
PRE-ESTABLISHED HARMONY
├── Monads don't interact
├── God synchronized them at creation
├── Like two clocks keeping perfect time
└── Solves mind-body problem without interaction
PRINCIPLES
├── Identity of Indiscernibles: No two things exactly alike
├── Sufficient Reason: Nothing without a reason
├── Best of All Possible Worlds: God chose the best
└── Continuity: Nature makes no leaps
Theodicy: This is the best of all possible worlds
| Thesis | Description |
|---|---|
| No Innate Ideas | Mind begins as blank slate (tabula rasa) |
| Experience as Source | All knowledge derives from experience |
| Limits of Knowledge | We cannot know beyond experience |
| Analysis of Ideas | Break complex ideas into simple components |
Theory of Ideas:
LOCKEAN EPISTEMOLOGY
════════════════════
SOURCE OF IDEAS:
SENSATION REFLECTION
├── External world ├── Operations of mind
├── Through senses ├── Perception, memory, reasoning
└── Primary source └── Secondary source
TYPES OF IDEAS:
SIMPLE IDEAS
├── Cannot be further analyzed
├── Passive reception from experience
├── Examples: yellow, cold, hard, sweet
└── Building blocks
COMPLEX IDEAS
├── Mind combines simple ideas
├── Three types:
│ ├── Modes (modifications)
│ ├── Substances (collections)
│ └── Relations (comparisons)
└── Examples: beauty, gratitude, army, causation
Primary and Secondary Qualities:
| Primary | Secondary |
|---|---|
| In objects themselves | In perceiver |
| Extension, motion, number | Color, taste, sound |
| Resemble ideas | Don't resemble |
| Measurable | Subjective |
Personal Identity: Not same substance, but same consciousness
Immaterialism: Esse est percipi (To be is to be perceived)
BERKELEYAN IDEALISM
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THE ARGUMENT:
1. We perceive only ideas (Locke agrees)
2. Ideas can only exist in a mind (perception requires perceiver)
3. Material substance is supposed to cause ideas
4. But we have no idea of material substance!
└── Abstract idea of "matter" is incoherent
5. Therefore, "material substance" is meaningless
6. Objects = collections of ideas
7. What makes objects persist when unperceived?
└── God perceives all things always
AGAINST LOCKE:
├── Primary/secondary distinction fails
├── All qualities are ideas, all ideas are mind-dependent
├── "Material substance" is an empty abstraction
└── Abstract ideas are impossible
God's Role:
Impressions and Ideas:
HUMEAN EPISTEMOLOGY
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IMPRESSIONS IDEAS
├── Lively, vivid ├── Faint copies
├── Direct experience ├── Derived from impressions
└── Original └── Copies
RELATIONS OF IDEAS MATTERS OF FACT
├── Certain, necessary ├── Contingent
├── Deny → contradiction ├── Deny → no contradiction
├── Mathematics, logic ├── Empirical claims
└── A priori └── A posteriori
HUME'S FORK:
Any claim either concerns:
1. Relations of ideas (analytic, certain)
2. Matters of fact (synthetic, probable)
If neither, "commit it to the flames"
The Problem of Induction:
HUME'S PROBLEM
══════════════
We reason: The sun has risen every day, therefore it will rise tomorrow.
But this assumes: Nature is uniform (future will resemble past)
How do we know this?
├── Not by reason alone (no contradiction in nature changing)
├── Not by experience (circular—uses induction to prove induction)
└── Not at all! Habit and custom, not reason.
SKEPTICAL SOLUTION:
├── Cannot justify induction rationally
├── We form expectations through habit
├── This is natural, unavoidable
└── Live by natural belief, not rational proof
Causation:
HUME ON CAUSATION
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TRADITIONAL VIEW: Necessary connection between cause and effect
HUME'S ANALYSIS:
1. Constant conjunction (A always followed by B)
2. Contiguity in space and time
3. Temporal priority (A before B)
WHERE IS NECESSARY CONNECTION?
├── Not in objects (we see only succession)
├── Not in experience (no impression of necessity)
└── In the mind! (Habit creates expectation)
CONCLUSION:
├── Causation = regular succession + mental expectation
├── No real power in objects
└── "Necessary connection" is projection
Personal Identity:
Problem: How to preserve science while answering Hume's skepticism?
Solution: Transcendental idealism
KANT'S COPERNICAN REVOLUTION
════════════════════════════
TRADITIONAL VIEW:
Mind conforms to objects
(We passively receive information about world as it is)
KANT'S REVOLUTION:
Objects conform to mind
(Mind actively structures experience)
CONSEQUENCE:
├── We can know phenomena (appearances)
├── Cannot know noumena (things-in-themselves)
├── Synthetic a priori knowledge is possible
└── Through forms supplied by the mind
KANT'S DISTINCTIONS
═══════════════════
ANALYTIC SYNTHETIC
(Predicate in (Predicate adds to
subject) subject)
A PRIORI "All bachelors "7 + 5 = 12"
(Independent of are unmarried" "Every event has
experience) ✓ Everyone a cause"
accepts THE KEY QUESTION!
A POSTERIORI (Impossible— "The cat is on
(Dependent on analytic truths the mat"
experience) don't need ✓ Everyone
experience) accepts
The Central Question: How is synthetic a priori knowledge possible?
SPACE AND TIME
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NOT:
├── Properties of things-in-themselves
├── Abstract concepts derived from experience
└── Relations between things
BUT:
├── Forms of sensible intuition
├── Structures the mind imposes on experience
├── A priori conditions for perception
SPACE
├── Form of outer sense
├── Makes geometry possible
└── Necessary, a priori
TIME
├── Form of inner sense
├── All representations in time
├── Makes arithmetic possible
└── Necessary, a priori
The Categories: Pure concepts of understanding
THE TWELVE CATEGORIES
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QUANTITY QUALITY
├── Unity ├── Reality
├── Plurality ├── Negation
└── Totality └── Limitation
RELATION MODALITY
├── Substance ├── Possibility
├── Causality ├── Actuality
└── Reciprocity └── Necessity
APPLICATION:
├── Categories structure all experience
├── Cannot be derived from experience
├── But only apply within experience
└── No transcendent use (beyond experience)
Transcendental Deduction:
Transcendental Illusion: Reason tries to extend beyond experience
THE THREE IDEAS OF REASON
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SOUL (Psychology)
├── Rational psychology claims to prove immortality
├── Paralogisms: invalid arguments about the self
└── "I think" ≠ substantial soul
WORLD (Cosmology)
├── Antinomies: contradictory conclusions
├── Thesis vs. Antithesis both provable
├── Example: World has beginning / No beginning
└── Shows: Questions transcend possible experience
GOD (Theology)
├── Traditional proofs fail
├── Ontological: Existence not a predicate
├── Cosmological: Misuse of causality
├── Teleological: At best shows designer, not God
└── But: God as regulative idea, postulate of practical reason
| Term | Philosopher | Meaning |
|---|---|---|
| Cogito | Descartes | "I think" — first certainty |
| Res cogitans | Descartes | Thinking substance (mind) |
| Res extensa | Descartes | Extended substance (body) |
| Clear and distinct | Descartes | Criterion of truth |
| Substance | Spinoza | That which is in itself |
| Attribute | Spinoza | What constitutes substance |
| Mode | Spinoza | Modification of substance |
| Monad | Leibniz | Simple substance |
| Pre-established harmony | Leibniz | God's synchronization |
| Tabula rasa | Locke | Blank slate |
| Primary qualities | Locke | In objects (extension) |
| Secondary qualities | Locke | In perceiver (color) |
| Esse est percipi | Berkeley | To be is to be perceived |
| Impressions | Hume | Vivid, original perceptions |
| Ideas | Hume | Faint copies of impressions |
| Phenomenon | Kant | Appearance, object of experience |
| Noumenon | Kant | Thing-in-itself, beyond experience |
| Transcendental | Kant | Concerning conditions of experience |
| Category | Kant | Pure concept of understanding |
| Synthetic a priori | Kant | Necessary truths about experience |
thoughts/knowledge/: Epistemology, skepticismthoughts/consciousness/: Mind-body problemthoughts/existence/: Substance metaphysicsmethods.md: Methodical doubt, empirical analysis, transcendental methodvocabulary.md: Technical terms glossaryfigures.md: Major philosophers with key worksdebates.md: Central controversiessources.md: Primary texts and scholarship
