Metaphysics · All lessons
Metaphysics is the branch of philosophy that asks the most basic questions of all: what exists, and what is reality fundamentally like? This lesson explains what metaphysics is, the kinds of questions it asks, how it differs from the sciences and from other branches of philosophy, and why it underlies almost everything else we think.
Most fields take the existence of their subject for granted and study how it behaves. A physicist studies how matter and energy move; a biologist studies how living things grow and reproduce; a historian studies what people did. Metaphysics steps back one level further and asks the questions those fields assume answers to: what is it for something to exist at all? What kinds of things are real? What is the basic structure of reality?
Because of this, metaphysics is sometimes described as the study of being as such — not this or that particular thing, but anything whatever, just insofar as it is.
The word has an almost accidental origin. When early editors organised Aristotle's works, they placed a group of writings on these very general questions after his writings on nature, or physics. In Greek that is ta meta ta physika — literally 'the things after the Physics.' Aristotle himself called the subject 'first philosophy.' Over time 'metaphysics' came to name the study of reality at its most general level.
Metaphysics is really a family of connected questions. Some of the main ones include:
It is tempting to think science has simply replaced metaphysics. But the two ask different kinds of question. Science investigates how the things that exist behave, using observation and experiment. Metaphysics asks what kinds of things there are in the first place, and what general categories — object, property, cause, time — we need to make sense of anything at all. These are questions that no single experiment can settle, because any experiment already assumes answers to them.
That said, the two are not strangers. Discoveries in physics about space, time, and causation bear directly on metaphysical theories, and good metaphysics tries to be consistent with our best science.
A quick way to see what is distinctive about metaphysics is to compare the four big branches by the question each asks:
The same topic can be approached by different branches. 'Free will' is a metaphysical question about what is real; 'can we ever know whether we have free will?' is an epistemological one; 'are we responsible for our actions?' shades into ethics.
Metaphysics can look abstract, but its assumptions are everywhere. Whether you think people are genuinely responsible for what they do, whether you take mathematics to describe something real, whether you believe the mind is merely the brain or could survive it — each of these is a metaphysical commitment, whether or not it is ever stated out loud. Bringing such assumptions into the open, and asking whether they can be defended, is the work of metaphysics.