Theodore Sider is Professor of Philosophy at New York University. He is the author of Four-Dimensionalism and (with Earl Conee) Riddles of Existence.

John Hawthorne is Waynflete Professor of Metaphysical Philosophy at the University of Oxford. He is the author of Metaphysical Essays, and has published widely in metaphysics, epistemology, philosophy of language, and Leibniz studies.

Dean W. Zimmerman is Associate Professor in the Philosophy department at Rutgers University. He is editor of Oxford Studies in Metaphysics, and author of numerous articles in metaphysics and philosophy of religion.