# Metaphysics ## Intro Metaphysics is the study of what there is and what it is like at the most general level. Not what chemistry is made of or what history records, but the questions underneath all of those: what does it take for something to exist, what kinds of things are there, what makes a thing the same thing over time, what is a cause, and is anything necessary rather than merely happening to be the case. The name is an accident. An early editor of [Aristotle](/codex/aristotle/) filed these writings after the volumes on physics and labelled them *ta meta ta physika*, the ones after the physics. Aristotle himself called the subject first philosophy, which is the better name, because every other discipline assumes answers to its questions without being able to supply them. That last point is why metaphysics matters here rather than being an academic speciality. Every worldview is a set of metaphysical commitments, whether or not anyone states them. - Someone who says only physical things exist has made a metaphysical claim, not a scientific discovery. No experiment could establish it, because the claim is about what kinds of experiments could count. - Someone who says every event has a cause has made a metaphysical claim, and the cosmological arguments turn on whether it survives. - Someone who says right and wrong are real features of the world rather than preferences has made a metaphysical claim about what sorts of properties exist. - Someone who says he only believes what science can demonstrate has made a claim science cannot demonstrate, which is why that position collapses under its own rule. So the apologetic value of metaphysics is not that it proves God directly. It is that the arguments are almost never won at the level people fight them. Disagreements that present as scientific or moral usually turn out, two or three questions in, to be disagreements about causation, about whether abstract objects exist, or about whether minds are the sort of thing matter could produce. Knowing where the real dispute lives is most of the work. Quick reply line: *"Every claim you have made tonight rests on a view about what exists and what causes what. Those are not scientific findings, they are the assumptions science runs on. So we are both doing metaphysics. The only question is whether we are doing it carefully."* ## In full Metaphysics is the philosophical discipline concerned with the fundamental structure of reality: existence, being, substance, essence, property, relation, causation, identity, modality (necessity and possibility), time, and the ultimate constituents of the world. Its central sub-branch is **ontology**, the inquiry into what kinds of things exist and how existence claims are to be understood; see [Meta-Ontology](/codex/meta-ontology/) for the second-order dispute about how ontological questions should be settled at all. The subject was pronounced dead more than once in the twentieth century, principally by logical positivism, which held that metaphysical statements were meaningless because unverifiable. The verification principle failed by its own test, being itself neither analytic nor empirically verifiable, and analytic metaphysics has been among the most active areas of philosophy since the 1970s. The premature obituary is worth remembering, because the popular-level claim that metaphysics was retired by science is roughly sixty years out of date. ## The core questions **Existence and being.** What is it for something to exist? Are there different modes of existence, so that numbers, fictional characters, holes and persons exist in different senses? Classical theism's central claim belongs here: God is not one being among others but subsistent being itself, which is treated at [Ipsum Esse Subsistens](/codex/ipsum-esse-subsistens/). **Substance and property.** What is a thing, as distinct from its features? The Aristotelian answer, substance as the bearer of properties, underwrites a great deal of Christian doctrine, including the vocabulary of the Trinity and the Incarnation. See [Relation (Thomist Metaphysics)](/codex/relation-thomist-metaphysics/) and [Universals](/codex/universals/) on whether properties are real entities, and [One and the Many Problem](/codex/one-and-the-many-problem/) on the unity-and-plurality question that runs beneath both. **Causation.** What is a cause, and must everything that begins have one? This is the most apologetically loaded topic in the field. See [Causal Principle](/codex/causal-principle/), and note that the dispute is genuinely metaphysical rather than empirical: the interpretation of quantum indeterminacy decides what the physics is evidence *for*. **Modality.** What could have been otherwise, and what could not? Necessity and possibility are the machinery of the ontological arguments and of any claim that God exists necessarily rather than contingently. **Identity and persistence.** What makes something the same thing across time and change? Bears directly on personal identity, resurrection and the endurance of the self. **Mind and matter.** Is the mental reducible to the physical? See [Substance Dualism](/codex/substance-dualism/), [Property Dualism](/codex/property-dualism/), [Consciousness](/codex/consciousness/) and [Access and Phenomenal Consciousness](/codex/access-and-phenomenal-consciousness/). **Time.** Is the passage of time real or a feature of our perspective? See [A-Theory vs B-Theory of Time and Divine Foreknowledge](/codex/a-theory-vs-b-theory-of-time-and-divine-foreknowledge/) and [Infinity](/codex/infinity/), both of which the cosmological arguments depend on. ## The major positions | Position | Core claim | Codex treatment | |---|---|---| | **Naturalism** | Reality is exhausted by the natural world; no supernatural entities | [Naturalism](/codex/naturalism/) | | **Materialism** | Everything that exists is material or wholly dependent on the material | [Materialism](/codex/materialism/) | | **Idealism** | Reality is fundamentally mental | [Idealism](/codex/idealism/) | | **Substance dualism** | Mind and body are distinct kinds of substance | [Substance Dualism](/codex/substance-dualism/) | | **Property dualism** | One substance, two irreducible kinds of property | [Property Dualism](/codex/property-dualism/) | | **Classical theism** | God is subsistent being itself, simple, eternal, pure act | [Divine Simplicity](/codex/divine-simplicity/), [Actus Purus](/codex/actus-purus/) | Two positions frequently mistaken for metaphysical neutrality are in fact substantive metaphysical commitments: [Methodological Naturalism](/codex/methodological-naturalism/), which is a working rule about what counts as a scientific explanation and is often smuggled into a claim about what exists, and [Scientism](/codex/scientism/), which is self-refuting for the reason given above. ## Why apologetics runs through it Four of the codex's main argumentative lines are metaphysical arguments before they are anything else. 1. **The cosmological family** turns on causation, contingency and the possibility of an actual infinite. Whether the universe needs an explanation is not settled by cosmology; it is settled by [Principle of Sufficient Reason](/codex/principle-of-sufficient-reason/) and by what a cause is. See [Cosmological Arguments](/codex/cosmological-arguments/) and [Kalam Cosmological Argument](/codex/kalam-cosmological-argument/). 2. **The ontological family** turns entirely on modality. Whether a maximally great being's possible existence entails its actual existence is a question about possible worlds, not about evidence. 3. **The moral family** turns on whether moral properties are real, and if so what kind of thing they are. See [Divine Command Theory](/codex/divine-command-theory/) and [Euthyphro Dilemma](/codex/euthyphro-dilemma/). 4. **The mind arguments** turn on whether consciousness and rationality can be produced by unguided physical processes. See [Argument from the Reliability of Reason](/codex/argument-from-the-reliability-of-reason/). The practical consequence: an opponent who declares metaphysics meaningless has not escaped these questions, he has adopted answers to them without examination. Naming that is usually more productive than arguing the surface topic. ## Common misconceptions - **"Metaphysics means crystals and energy fields."** A twentieth-century bookshop usage, unrelated to the discipline. Worth clarifying early, because the equivocation costs the argument credibility with an audience. - **"Science replaced metaphysics."** Science presupposes metaphysics: that there is a mind-independent world, that it is intelligible, that induction is reliable, that observation tracks reality. None of these are scientific results. - **"Metaphysical claims are unfalsifiable, so they are worthless."** The demand is itself unfalsifiable. Metaphysical theories are assessed for coherence, explanatory power, parsimony and fit with what else is known, which is how theory choice works in the sciences too. - **"It is all just word games."** Some of it is, as in any field. But whether the universe began, whether minds are physical, and whether moral facts exist are not verbal disputes, and their answers change what a person should do. ## See also - [Meta-Ontology](/codex/meta-ontology/), how ontological disputes should be adjudicated - [Causal Principle](/codex/causal-principle/), the most apologetically loaded question in the field - [Universals](/codex/universals/), whether properties are real entities - [One and the Many Problem](/codex/one-and-the-many-problem/), unity and plurality - [Infinity](/codex/infinity/), actual versus potential infinites - [Naturalism](/codex/naturalism/), the principal rival framework - [Materialism](/codex/materialism/), its most common form - [Idealism](/codex/idealism/), the mind-first alternative - [Substance Dualism](/codex/substance-dualism/), mind and body as distinct substances - [Property Dualism](/codex/property-dualism/), one substance with irreducible mental properties - [Consciousness](/codex/consciousness/), the phenomenon that resists reduction - [Methodological Naturalism](/codex/methodological-naturalism/), a rule of method often mistaken for a discovery - [Scientism](/codex/scientism/), the self-refuting restriction - [Divine Simplicity](/codex/divine-simplicity/), classical theism's central metaphysical commitment - [Actus Purus](/codex/actus-purus/), God as pure actuality - [Ipsum Esse Subsistens](/codex/ipsum-esse-subsistens/), God as subsistent being itself - [Relation (Thomist Metaphysics)](/codex/relation-thomist-metaphysics/), the relational apparatus behind Trinitarian doctrine - [Zero and the Metaphysics of Nothing](/codex/zero-and-the-metaphysics-of-nothing/), what nothing is and is not - [Aristotle](/codex/aristotle/), the discipline's founder - [Thomas Aquinas](/codex/thomas-aquinas/), the classical Christian synthesis
## Common questions this page answers **Q: What is metaphysics in simple terms?** It is the study of what exists and what reality is fundamentally like, at a level more general than any particular science. It asks what it takes for something to exist, what kinds of things there are, what a cause is, what makes something the same thing over time, and what could or could not have been otherwise. Aristotle called it first philosophy, because every other field assumes answers to these questions without being able to supply them. **Q: Didn't science make metaphysics obsolete?** No, and the attempt to retire it failed on its own terms. Logical positivism held that unverifiable claims are meaningless, but that principle is itself neither a logical truth nor empirically verifiable, so it fails its own test. Science also depends on metaphysical commitments it cannot establish: that a mind-independent world exists, that it is intelligible, and that induction is reliable. **Q: Why does metaphysics matter for apologetics?** Because most apologetic disputes are metaphysical disputes wearing other clothes. Whether the universe needs a cause is a question about causation, not cosmology. Whether moral facts exist is a question about what kinds of properties there are. Whether minds are physical decides what an argument from consciousness can show. Arguing the surface topic while the real disagreement sits one level down is how these exchanges stall. **Q: Is metaphysics the same thing as the metaphysical section in a bookshop?** No. The bookshop sense, covering crystals, auras and energy healing, is a twentieth-century usage with no connection to the philosophical discipline. The academic subject is a rigorous branch of philosophy concerned with existence, causation, identity and necessity. The equivocation is worth clearing up early in any conversation, because it invites an audience to dismiss the argument before it starts. **Q: What is the difference between metaphysics and ontology?** Ontology is a sub-branch of metaphysics. Ontology asks specifically what kinds of things exist, while metaphysics covers that plus causation, identity, necessity and possibility, time, and the nature of substance and property. A further level up, meta-ontology asks how ontological disputes ought to be settled in the first place.