Does the real world, defined as a world of objects that exist independent of human interests, concerns, and cognitive activities, really exist? Jan Westerhoff argues that we have good reason to believe it does not. His discussion considers four main facets of assuming an external world, ranging from the existence of a separate external and internal world (comprising various mental states congregated around a self), to the existence of an ontological foundation that grounds the existence of all the entities in the world, and the existence of an ultimately true theory that provides a final account of all there is. As Westerhoff discusses the reasons for rejecting the postulation of an external world behind our representations, he asserts that the internal world is not as epistemically transparent as is usually assumed, and that there are good reasons for adopting an anti-foundational account of ontological dependence. Alongside this discussion he considers fundamental philosophical questions in metaphysics and the philosophy of knowledge, such as the existence of self and a ground of reality. Drawing on conclusions from the ancient Indian philosophical system of Madhyamaka Buddhism closely, Westerhoff defends his stance in a purely Western philosophical framework, and affirms that ontology, and philosophy more generally, must not be conceived as providing an ultimately true theory of the world.