Metaphysics
Metaphysics asks the most fundamental questions philosophy can pose: What exists? What is the nature of reality? What am I? These questions resist empirical resolution — not because they are unscientific, but because they concern the framework within which science itself operates. This skill covers the major branches of metaphysical inquiry with worked examples from both Western and Buddhist traditions.
Agent affinity: nagarjuna (metaphysics and philosophy of mind, Sonnet), beauvoir (existentialism and phenomenology, Opus)
Concept IDs: philo-thought-experiments, philo-philosophical-questioning
The Metaphysics Landscape at a Glance
| # | Domain | Core question | Key thinkers | |---|--------|---------------|--------------| | 1 | Ontology | What exists? | Aristotle, Quine, Meinong | | 2 | Substance and properties | What are things made of? | Aristotle, Locke, Bundle theorists | | 3 | Universals vs. particulars | Do properties exist independently? | Plato, Armstrong, trope theorists | | 4 | Free will and determinism | Are our choices free? | Hume, Kant, Frankfurt, van Inwagen | | 5 | Personal identity | What makes me the same person over time? | Locke, Parfit, Olson | | 6 | Philosophy of mind | What is consciousness? | Descartes, Dennett, Chalmers, Nagel | | 7 | Causation | What makes one thing cause another? | Hume, Lewis, Anscombe | | 8 | Time | Is the past real? The future? | McTaggart, Prior, Sider | | 9 | Possible worlds | What could have been? | Leibniz, Lewis, Kripke | | 10 | Buddhist metaphysics | What is emptiness? | Nagarjuna, Vasubandhu, Candrakirti | | 11 | Process philosophy | Is reality made of processes or things? | Whitehead, Rescher |
1 — Ontology
Core question. What exists? What does it mean for something to exist?
Quine's Criterion
W. V. O. Quine proposed that we are committed to the existence of whatever our best scientific theories quantify over. "To be is to be the value of a bound variable." If physics requires quantifying over electrons, we are ontologically committed to electrons. If mathematics requires quantifying over numbers, we are committed to numbers.
Worked example — The ontological status of mathematical objects:
Consider the statement: "There exists a prime number greater than one trillion." If we take this at face value, we are committed to the existence of numbers. But where do numbers exist? They are not physical objects. This generates the problem of abstract objects:
- Platonism: Numbers exist in an abstract realm, independent of minds and physical reality.
- Nominalism: Numbers do not exist. Mathematical statements are useful fictions or shorthand for physical facts.
- Fictionalism (Field): Mathematics is literally false (there are no numbers), but it is useful because it conservatively extends true physical theories.
The Problem of Non-Existent Objects
Can we think about things that do not exist? We seem to — we think about unicorns, Sherlock Holmes, and the largest prime number (which we can prove does not exist). Meinong (1904) distinguished between existence (actual things), subsistence (abstract objects), and Aussersein (objects that have neither). Russell (1905) dissolved the problem via his theory of definite descriptions, reducing apparent reference to non-existent objects to quantified statements that can be straightforwardly false.
2 — Substance and Properties
The Substratum View
Locke (1689) argued that substances are "something I know not what" — bare substrata that support properties. A table has the property of being brown, being hard, being rectangular — but what is the table apart from these properties? The substratum is what remains when you strip away all the properties.
Objection: If the substratum has no properties of its own, it is featureless — and a featureless thing seems like nothing at all.
Bundle Theory
The alternative: there is no substratum. A thing IS the bundle of its properties. A table is brownness + hardness + rectangularity + spatial location + ... co-located at a point.
Objection (the identity of indiscernibles): If two objects had exactly the same properties, bundle theory implies they would be the same object. But can't there be two qualitatively identical spheres in an otherwise empty universe? Max Black's (1952) thought experiment suggests yes — which challenges bundle theory.
Worked example — Black's two spheres:
Imagine a universe containing nothing but two perfectly identical iron spheres, one mile apart. They have the same size, shape, mass, temperature, and every other property. Are they the same object? Intuitively, no — there are two of them. But if they share all properties (including relational properties, since the universe is symmetric), bundle theory cannot distinguish them. This suggests that either there is something more to objects than their properties (a "bare particular") or that our spatial framework smuggles in a hidden individuating property.
3 — Universals vs. Particulars
The problem. Multiple things can share the same property — this apple and that fire truck are both red. What explains this? Is there one thing — redness — that both objects participate in? Or is each instance of red a distinct entity?
| Position | Claim | Problem | |----------|-------|---------| | Platonic realism | Universals exist independently (in a "third realm") | How do abstract universals connect to concrete particulars? (Third man argument) | | Aristotelian realism | Universals exist but only as instantiated in particulars | What about uninstantiated universals (properties nothing actually has)? | | Nominalism | Only particulars exist; "universals" are just names | What grounds the resemblance between particulars called by the same name? | | Trope theory | Each instance is a particular property (a "trope"); resemblance between tropes is primitive | Still needs to explain exact resemblance |
Worked example — The third man argument (Plato's Parmenides):
Suppose there is a Form of Largeness that explains why large things are large. Now consider: the Form of Largeness and the large things share the property of being large. By the original reasoning, there must be a second Form — the Form of Largeness-2 — to explain what they share. But then Largeness-2 and Largeness also share something, requiring Largeness-3, and so on infinitely. This regress was raised by Plato himself as a problem for his own theory — intellectual honesty of the highest order.
4 — Free Will and Determinism
The problem. If every event is determined by prior causes and the laws of nature, then my actions are determined. If my actions are determined, it seems I could not have done otherwise. If I could not have done otherwise, am I free? Am I morally responsible?
The Three Positions
| Position | Free will? | Determinism? | Key thinkers | |----------|-----------|--------------|--------------| | Hard determinism | No | Yes | d'Holbach, Pereboom | | Libertarianism (metaphysical) | Yes | No | Chisholm, Kane, van Inwagen | | Compatibilism | Yes | Yes (or irrelevant) | Hume, Frankfurt, Dennett |
Frankfurt Cases (1969)
Harry Frankfurt devised thought experiments to challenge the principle of alternate possibilities (PAP) — that moral responsibility requires the ability to have done otherwise.
Worked example — Frankfurt's counterfactual intervener:
Jones decides, entirely on his own, to vote for candidate A. Unbeknownst to Jones, Black — a neuroscientist — has implanted a device that would force Jones to vote for A if he showed any inclination to vote otherwise. As it happens, Jones votes for A voluntarily; the device is never triggered.
Analysis: Jones could not have done otherwise (Black's device would have intervened). Yet Jones seems morally responsible for his vote — he chose it freely, for his own reasons, without any interference. If this is right, PAP is false: moral