This Element covers several core topics in metaontology, providing systematic albeit partial coverage of this field of metaphysics.

Metaontology is the branch of philosophy that focuses on questions that naturally arise when doing ontology. This Element offers the reader (some of) the elements of metaontology by way of an opinionated overview of (some of) its central arguments and positions. The first section of this Element focuses on whether there are nonexistent objects. It discusses historical figures such as Suarez, Brentano, Twardowski, and Meinong, as well as contemporary figures such as Lewis, van Inwagen, Thomasson, and Zalta. The second section focuses on whether ontological questions are trivial to answer and whether ontological debates are merely verbal debates. Can there be different concepts of existence or different meanings of 'exists' or other ontological expressions? If ontological questions are nontrivial, are they nontrivial only if a substantive metaphysical view is true? Even if there aren't different senses of 'exist,' might there be different modes of being or ways to exist?