What are we committed to?
Object, property, relation, number?
Ordinary and scientific language can carry hidden ontological commitments.
Side 92
Metaphysics
A study of the most general structure of reality. Metaphysics asks what exists, what kinds of things exist, how they depend on one another, what makes them persist, and what it means for something to be possible or necessary.
existence→category→relation→dependence→possibility
06metaphysical lenses
05ontological questions
05dependence relations
92Side
Metaphysics begins with the apparently simple question: what is there?
The difficulty begins immediately because objects, properties, numbers, events, relations and possibilities do not all seem to exist in the same way.
What counts as existing?
Causal role, quantification, indispensability?
Different ontologies use different standards for admission.
What kind of thing is it?
Substance, event, process, property?
Classification changes what questions can be asked about persistence and causation.
Could it exist on its own?
Fundamental or derivative?
Some entities may exist only because others do.
How much ontology is needed?
Do not multiply entities lightly.
Explanatory gain must justify additional kinds of being.
Ontology asks what fundamental categories reality contains.
Metaphysical theories disagree about whether the world is fundamentally made of substances, events, processes, relations, structures or something else.
Things that bear properties.
Ordinary ontology treats tables, trees and people as persistent individuals.
Ways things are.
Redness, mass and fragility raise questions about universals versus particular instances.
Ways things stand to one another.
Distance, similarity and dependence may be as fundamental as individual things.
Things that happen.
Events provide one ontology for causation and change.
Continuities through change.
Process views treat persistence as ongoing activity rather than static substance.
Patterns of relations.
Structural realism asks whether structure may be more fundamental than individual objects.
Identity becomes difficult whenever something changes.
The problem is distinguishing change in a thing from replacement by a different thing.
| Problem | Question | Pressure point |
|---|---|---|
| Persistence | How does one thing exist across time? | Change of parts and properties |
| Composition | When do parts form one object? | Arbitrary groupings versus genuine wholes |
| Vagueness | Where do object boundaries begin and end? | Clouds, organisms, heaps |
| Ship of Theseus | Can all parts change while identity remains? | Material versus structural continuity |
| Coincidence | Can two objects occupy the same place? | Statue versus lump of clay |
Reality may be layered rather than flat.
Dependence relations ask what is fundamental and what exists or holds in virtue of something else.
Causal
One thing produces another.
Causal dependence unfolds through events or mechanisms.
Constitutive
Parts make up a whole.
A molecule depends on its constituents in a different way from an effect depending on a cause.
Grounding
One fact holds in virtue of another.
Grounding is proposed as a noncausal relation of metaphysical explanation.
Supervenience
No difference at one level without difference below.
Supervenience expresses dependence without specifying the mechanism.
Emergence
Higher-level properties arise from lower-level organization.
The metaphysical question is whether emergence is merely explanatory or ontologically novel.
Reality includes questions about what could have been otherwise.
Modality distinguishes what is actual from what is possible, necessary or impossible.
Could it have been true?
Possibility is broader than what actually happens.
Must it be true?
Logical, metaphysical and physical necessity may differ.
What would happen if things differed?
Counterfactual reasoning links modality to causation and explanation.
Which properties could an entity not lose?
Essence connects identity with modal structure.
Represent complete ways reality might be.
Possible-world semantics provides a formal language for modal claims.
Which possibilities are physically allowed?
Laws of nature constrain physical possibility without exhausting metaphysical possibility.
Metaphysics asks whether familiar reality is fundamental or derivative.
Science often reveals levels beneath ordinary objects; metaphysics asks what that reduction does and does not imply.
Ordinary objects
Start with persons, tables, organisms and institutions as apparently real entities.
Scientific decomposition
Analyze them into cells, molecules, particles, fields or structures.
Dependence
Ask whether higher-level entities are identical with, realized by or grounded in lower-level facts.
Autonomy
Ask whether higher-level explanations remain genuinely informative.
Fundamentality
Ask whether the search for a final basic level is coherent or necessary.
Metaphysicsexistence, identity and possibility
On What There IsW. V. O. Quine · ontological commitment
Groundingmetaphysical dependence
Modal Metaphysicspossibility, necessity and essence