Metaphysics Ontology

Metaphysics & Ontology Skill

Master the fundamental questions of metaphysics: What exists? What is being? What is the ultimate nature of reality?

Core Questions

Fundamental Issues

Ontology: What Exists?

Ontological Categories

ONTOLOGICAL LANDSCAPE
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CONCRETE PARTICULARS
├── Physical objects (tables, planets)
├── Mental events (thoughts, pains)
└── Persons

ABSTRACT OBJECTS (?)
├── Numbers, sets
├── Propositions
├── Properties/universals
└── Possible worlds

EVENTS AND PROCESSES
├── The Battle of Waterloo
├── The melting of ice
└── My walking to work

FACTS AND STATES OF AFFAIRS
├── That snow is white
├── The redness of the apple
└── The table's being square

Platonism vs. Nominalism

Platonism: Abstract objects exist

• Numbers exist independently of minds
• Properties are real universals
• Mathematical truth is discovery, not invention

Nominalism: Only particulars exist

• No abstract objects
• "Redness" is just a word for similar things
• Mathematical objects are useful fictions

Substance and Properties

Substance Theories

Aristotelian Substance:

• Primary substances: individual things (this horse)
• Secondary substances: kinds (horse, animal)
• Substances persist through change; accidents don't

Bundle Theory:

• No underlying substance
• Objects = bundles of properties
• Problem: What ties the bundle together?

Substratum Theory:

• Bare particulars underlie properties
• Problem: What is bare substratum? Unknowable?

Properties

Universals vs. Tropes:

Identity and Persistence

Personal Identity

Theories:

PERSONAL IDENTITY THEORIES
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PSYCHOLOGICAL CONTINUITY
├── Memory, personality, beliefs
├── Locke: consciousness makes identity
├── Parfit: What matters isn't identity
└── Problems: Fission, amnesia

BIOLOGICAL CONTINUITY
├── Same organism = same person
├── Animalism (Olson)
└── Problems: Transplant cases

SOUL/SUBSTANCE VIEW
├── Immaterial soul persists
├── Problems: Interaction, detection
└── Forensic vs. metaphysical identity

Ship of Theseus

SHIP OF THESEUS
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Original ship's planks gradually replaced.
Is it still the same ship?

VARIANT: Old planks reassembled into second ship.
Which is the original?

POSITIONS:
├── Neither (no real identity)
├── Repaired ship (spatial continuity)
├── Reassembled ship (material continuity)
└── Both partially (graded identity)

Causation

Theories

Regularity Theory (Hume):

• Causation = constant conjunction
• No necessary connection
• "Cement of the universe" is just habit

Counterfactual Theory (Lewis):

• C causes E iff: If C hadn't occurred, E wouldn't have
• Analyzed via possible worlds

Powers/Dispositions:

• Causes have intrinsic causal powers
• Salt's solubility is real property
• Not reducible to regularities

Process/Mechanism:

• Causation = physical process
• Transfer of energy, momentum
• Tracing causal history

Modality

Possible Worlds

Modal Claims:

• Necessarily P: P is true in all possible worlds
• Possibly P: P is true in some possible world
• Contingently P: P is true but could be false

What Are Possible Worlds?:

POSSIBLE WORLDS REALISM
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MODAL REALISM (Lewis)
├── Possible worlds are concrete realities
├── As real as actual world
├── "Actual" is indexical (like "here")
└── Controversial but powerful

ERSATZISM
├── Possible worlds are abstract objects
├── Sets of propositions, or
├── Maximal states of affairs
└── More conservative

FICTIONALISM
├── Possible worlds are useful fictions
├── No commitment to existence
└── Instrumentalist reading

Essence and Necessity

Essential Properties: Properties a thing must have to be that thing Accidental Properties: Properties a thing happens to have

Kripkean Essentialism:

• Origin is essential (you couldn't have different parents)
• Natural kinds have essences (water = H₂O necessarily)
• Names are rigid designators

Time

Theories of Time

A-Theory (Tensed):

• Past, present, future are real
• Present is metaphysically special
• Time flows

B-Theory (Tenseless):

• Only earlier-than, simultaneous, later-than relations
• No privileged present
• "Block universe" — all times equally real

Persistence Through Time

Endurantism: Objects are wholly present at each moment Perdurantism: Objects have temporal parts (stages)

PERSISTENCE VIEWS
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ENDURANTISM               PERDURANTISM
├── Object wholly         ├── Object has temporal parts
│   present at each time  │   (like spatial parts)
├── Properties change     ├── Different stages have
│   (intrinsic change)    │   different properties
└── Intuitive but         └── Handles change better but
    faces puzzles             counterintuitive

Composition

The Special Composition Question

When do parts compose a whole?

Universalism: Any objects compose something Nihilism: No composite objects exist Restricted: Some conditions required (contact, life, etc.)

Mereology

• Part-whole relations
• Proper vs. improper parts
• Transitivity of parthood
• Supplementation principles

Key Vocabulary

Integration with Repository

Related Themes

• thoughts/existence/: Being, reality, metaphysics

Thought Experiments

• Ship of Theseus
• Teletransporter
• Twin Earth (for natural kinds)