How do we sort out what’s real from what only seems to be? This is the central question of metaphysics - the wing of philosophy that tries to sort out what it is to exist, and where we fit in the grand scheme of things. a primer takes us on a light-hearted tour of some of the great metaphysical schemes on offer - from Heraclitus and Parmenides to Aristotle and Spinoza to some of the thrilling views offered in modern physics.