# Philosophy 101: Metaphysics - What is Real?

## Beyond Physics

If Physics is the study of how the physical world moves and interacts, **Metaphysics** is the study of what the world *is*.

It asks the questions that science takes for granted. Science asks "How does gravity work?" Metaphysics asks "What is a 'law of nature'?"

## Ontology: The Furniture of the Universe

**[Ontology](/vocab/ontology)** is the study of *being*. It's like taking an inventory of the universe.

* Do chairs exist? Yes.

* Do numbers exist? Ideally, yes, but you can't trip over the number 4.

* Do holes exist? A hole is just the *absence* of stuff, so is it a "thing"?

## The Mind-Body Problem

This is the big one.

* **Materialism:** Everything is physical matter. Your thoughts are just neurons firing. Love is just dopamine.

* **Dualism:** The mind and body are separate. There is a "ghost in the machine."

If you are just atoms, how do you have **[Qualia](/vocab/qualia)**—the subjective feeling of the redness of a rose? Atoms aren't red. They don't feel. How does meat become magic?

## Free Will vs. Determinism

If the universe follows physical laws, and your brain is physical, then every thought you have is just the result of the previous physical state.

* **Determinism:** You have no free will. You were always going to read this sentence.

* **Libertarian Free Will:** You genuinely could have done otherwise.

* **Compatibilism:** A messy middle ground where we redefine "free will" to make everyone happy.

## Recommended Resources

**1. The Book:**

* **"Metaphysics: A Very Short Introduction" by Stephen Mumford**.

* Does exactly what it says on the tin.

**2. The Thought Experiment:**

* **The Ship of Theseus.**

* If you replace every plank of a ship one by one, is it still the same ship? If you teleport to Mars, but the machine destroys your body here and builds a copy there, is it still *you*?

Next, we finish with the most practical question: **How should we live?** (Ethics).