What Is Metaphysics? Questions, Theories and Philosophers

Metaphysics is the branch of philosophy that asks what reality is fundamentally like: what exists, what kinds of thing there are, and how they hang together. It covers being, mind, time, space, cause, possibility and free will — questions no experiment settles on its own, because the disagreement is about what the observations mean.

Physics can tell you how a river flows. Metaphysics asks whether the river is a thing or an event, and whether it is the same river tomorrow. This guide sets out what metaphysics studies, its rival answers, how every major tradition has approached it, and where to start.

Where does the word “metaphysics” come from?

The word comes from the Greek ta meta ta phusika, “the things after the physics”. Aristotle wrote a set of treatises on what he called first philosophy: the study of being as being. When his works were edited and catalogued, traditionally by Andronicus of Rhodes in the first century BCE, these treatises were placed after the Physics, and the shelf position became the name.

The accident fits: metaphysics asks not how particular things behave, but what it is for anything to exist, change, cause or be possible.

In bookshops, “metaphysical” often labels books on spirituality, energy healing or the occult. That popular sense is a different thing. In philosophy, metaphysics is a field of argument: claims are stated precisely, tested against objections and set beside their rivals. It is as open to atheists and materialists as to believers — materialism is itself a metaphysical position.

What does metaphysics study? The branches of metaphysics

Metaphysics is less one question than a family of them. On The Coordinates, the site’s map of philosophy, Root I gathers them into these branches:

• Ontology — what there is, and what it takes for something to exist. It includes substance, universals and particulars, parts and wholes and abstract objects such as numbers.
• Philosophical cosmology — why there is a universe at all, whether it had a first cause, and whether it could have had different laws. Scientific cosmology asks how the universe developed; this asks why it is there.
• Philosophy of mind — what minds are, how they relate to bodies (the mind–body problem), how thoughts can be about anything, what makes you the same person over time, and why there is conscious experience at all.
• Time and space — whether time passes, how things persist through change, what causation is, and whether space would remain if every object vanished.
• Modality — possibility and necessity, including talk of possible worlds.
• Free will and determinism — whether you could have done otherwise.
• Natural theology — whether argument alone can settle whether God exists.
• Laws of nature and emergence — whether laws govern events or only describe them, and whether biology is “just” chemistry.
• Meta-metaphysics — whether metaphysical disputes are about anything at all.

The 24 cards of Root I come from The Coordinates of Thought by Syed Raheel Shahzad; the full tree follows. Questions marked △ are contested: philosophers disagree about the question itself, not only about the answer.

Examples of metaphysical questions

The quickest way to see what metaphysics is about is to read its questions. Each of these heads a card on The Coordinates:

• Is a river a thing, or an event?
• A tomato and a fire engine are both red. Is there something they share?
• Does the number seven exist?
• Why is there something rather than nothing?
• How can a thought move an arm?
• Are you the same person you were at five?
• Why isn’t it all dark inside? — that is, why is there any conscious experience?
• Does time pass, or does it only seem to?
• What do you actually see when you see one thing cause another?
• Could you have done otherwise?
• Is chemistry just physics, and biology just chemistry?

More data would not settle any of them. A brain scan shows which neurons fire when you decide, but not whether the decision was free. These are questions about how to interpret what we already know.

The main theories in metaphysics: materialism, idealism, dualism and more

The oldest question in metaphysics is the one on the ontology card: what is there? Five broad answers recur across history and across cultures.

Position	The claim	Held in some form by
Materialism (physicalism)	Only physical things exist; minds are physical states or processes	Democritus and the Greek atomists; the Cārvāka school in India; many contemporary analytic philosophers
Idealism	Only minds and their contents exist, or the mental comes first	George Berkeley; Yogācāra Buddhism, on a common reading of Vasubandhu; British idealists such as McTaggart
Dualism	Mind and matter are both real and irreducibly different	René Descartes; the Sāṃkhya school in India, which separates pure consciousness from matter
Neutral monism	One kind of stuff underlies both, and it is neither mental nor physical	William James and Bertrand Russell, in parts of their work
Pluralism	There are several irreducible kinds of thing	The Vaiśeṣika school, with its list of basic categories

The same split runs through narrower questions. On the philosophy of mind card it becomes identity theory, functionalism, property dualism, panpsychism and eliminativism. On substance it becomes a contest between those who take enduring things as basic, like Aristotle, and those who take processes as basic, like Heraclitus, Zhuangzi and Whitehead. On time it becomes presentism, the growing block and eternalism.

Some traditions refuse the menu altogether. Śaṅkara’s Advaita Vedānta holds that only Brahman, undivided consciousness, is real in the full sense, and the world of many separate things is appearance. Nagarjuna’s Madhyamaka argues that nothing at all has an intrinsic nature of its own, so neither matter nor mind can serve as the foundation. They are rival answers to the same question, not footnotes to a Western list.

How different traditions approach metaphysics

Every tradition has a metaphysics, though not every one uses the word. A few landmarks from the figures on Root I’s cards:

• Greek. Parmenides argued that what is cannot come from what is not, so change must be an illusion; Heraclitus made flux fundamental. Plato placed the Forms outside space and time. Aristotle answered with substances — this horse, this tree — and an account of being as being. See Greek and Roman philosophy.
• Indian. Śaṅkara identified the deepest self (ātman) with Brahman, the one reality. The Vaiśeṣika school catalogued the kinds of real thing, space among them, and Jain thinkers held the cosmos to be without beginning. See Indian philosophy.
• Buddhist. Nagarjuna argued that everything arises in dependence on other things and is therefore “empty” of intrinsic nature. Vasubandhu defended momentariness — nothing persists; continuity is inferred. See Buddhist philosophy.
• Chinese. Laozi’s Daodejing speaks of a Dao that comes before and exceeds every name. Zhuangzi treated the world as ceaseless transformation; Fazang’s Huayan Buddhism held that each part and the whole interpenetrate; Wang Fuzhi built a metaphysics of qi, vital stuff in constant change. See Chinese philosophy.
• Islamic. Ibn Sina distinguished what a thing is (its essence) from the fact that it exists, and argued from contingent things to a Necessary Existent. Al-Ghazali denied that created things cause anything by their own power, and Ibn Rushd defended natural causes against him. Mulla Sadra later made existence itself primary and in constant motion. See Islamic philosophy.
• Modern European. Descartes split mind from matter, and Elisabeth of Bohemia pressed him on how an immaterial mind could move a body. Spinoza made thought and extension attributes of one substance; Leibniz asked why there is something rather than nothing; Hume doubted we ever perceive a necessary connection between cause and effect; Kant argued that space and time are forms of our experience. Anton Wilhelm Amo, born on the Gold Coast and teaching in Germany, also wrote on mind and body. See modern European philosophy.
• Analytic and continental. Quine recast ontology as the question of what our best theories commit us to; Saul Kripke and David Lewis revived talk of necessity and possible worlds. Heidegger argued that Western metaphysics had forgotten the question of the meaning of Being itself, and Whitehead built a philosophy of process. See analytic and continental philosophy.

The philosophers named most often across the metaphysics cards, with their dates and traditions:

Metaphysics vs epistemology

Metaphysics and epistemology are easily confused. Metaphysics asks what is real. Epistemology asks how we know, and what entitles us to believe anything.

	Metaphysics	Epistemology
Core question	What exists, and what is it like?	What can we know, and how?
Typical questions	Does time pass? Is the mind the brain? Do numbers exist?	What turns a true belief into knowledge? Can perception be trusted? How do you know you are not dreaming?
Sample positions	Materialism, idealism, dualism; presentism, eternalism	Empiricism, rationalism; foundationalism, coherentism; skepticism

The two constantly meet. If numbers exist outside space and time, as Platonists hold, how could objects that cause nothing ever be known? That puzzle, pressed by Paul Benacerraf, is metaphysical and epistemological at once. Doubt about the external world is a problem about knowledge; idealism’s answer to it is a claim about what exists.

Is metaphysics about anything? The meta-metaphysics debate

Critics have long doubted that metaphysical questions have answers, or even meaning. The meta-metaphysics card is marked △ because philosophers still disagree about this.

• David Hume held that a book containing neither reasoning about quantity and number nor reasoning from experience about matters of fact should be committed to the flames.
• Immanuel Kant argued that reason, when it tries to reach beyond any possible experience, runs into contradictions, so traditional metaphysics oversteps its limits.
• The logical positivists, including Rudolf Carnap and A. J. Ayer, held that metaphysical claims cannot be verified and are therefore meaningless. Carnap later argued that “do numbers exist?” is either trivial inside a chosen framework of language or, asked from outside it, a practical choice of language.
• W. V. O. Quine replied that there is no clean line between choosing a language and describing the world, which reopened ontology as continuous with science.
• Ludwig Wittgenstein’s later work inspired quietism: the puzzles dissolve once we see how words are ordinarily used.
• Nagarjuna, many centuries earlier, argued that views positing intrinsic natures undermine themselves, and is often read as dissolving metaphysical theses rather than proposing a rival one.
• A revival since the later twentieth century, driven first by work on necessity and possible worlds and more recently by a neo-Aristotelian interest in grounding and fundamentality, treats metaphysical disputes as substantive.

The live question today is narrower than “is metaphysics nonsense?”. It is whether a particular dispute — over whether tables exist, or only particles arranged table-wise — is about the world or only about words.

Is metaphysics still relevant?

Its questions turn up wherever people argue about what something really is.

• Artificial intelligence. Whether a machine could be conscious, or understand anything, depends on what minds are; functionalists and identity theorists give different answers. See Philosophy of Artificial Intelligence.
• Law and blame. Responsibility, punishment and excuse all assume something about whether we could have done otherwise. The free will card notes that a majority of respondents to the 2020 PhilPapers Survey accepted or leaned towards compatibilism, yet the question remains open.
• Science. Physics describes time, laws and causes, but whether time really passes, or what makes something a law, is still disputed. Metaphysics is not an experimental science, but it has to answer to science.
• Everyday categories. Whether money, nations, races or genders are real, and in what sense, is a question of social ontology.

Recent conversations on the site:

How to start studying metaphysics

1. Begin with three questions. What is there?, Are you the same person you were at five? and Could you have done otherwise? are concrete, and each opens on to the rest of the field. All three are on the ten-question path in Philosophy for beginners.
2. Read one card at a time. Pick the answer you find most natural, then read its strongest objection.
3. Read across traditions. Set Nagarjuna beside Hume on causation, or the Buddha’s no-self view beside Locke on memory.
4. Read a first book. The titles below come from the site’s Book corner, beginner-friendly ones first.
5. Join a conversation. Browse Metaphysics and Mind & Self, or ask a question of your own.

Where do you stand?

Every question here has serious answers on more than one side. Pick a card, read the rival answers, then say which you find strongest and why. Members ask, reply and take sides; reading is free for everyone.

Join free Open The Coordinates

Next guideWhat Is Epistemology? The Theory of Knowledge, Its Questions and Thinkers