Is matter real? Are persons real? Is time real? This Very Short Introduction discusses what, if anything, is real by looking at a variety of arguments from philosophy, physics, and cognitive science. Jan Westerhoff shows that the question what is real? is not some esoteric puzzle that only philosophers ponder. Scientists also ask this question when they investigate whether candidates for the fundamental constituents of matter are actually out there or just a mere abstraction from a successful theory and cognitive scientists ask it when trying to find out which set of the bewildering array of data processed by our brain could constitute the basis for the self.

'What is real?' has been one of the key questions of philosophy since its beginning in antiquity. But it is not just a question that philosophers ask. This Very Short Introduction discusses what reality is by looking at a variety of arguments, theories, and thought-experiments from philosophy, physics, and cognitive science.