This talk was given on January 8, 2022 at the Dominican House of Studies as part of "The Eucharist," an intellectual retreat for the Thomistic Institute’s chapters at Auburn University and North Carolina State University. For more information on upcoming events, please visit our website at www.thomisticinstitute.org. About the speaker: Alexander Pruss has doctorates in philosophy and mathematics, and is currently Professor of Philosophy at Baylor University. His books include The Principle of Sufficient Reason: A Reassessment (Cambridge University Press), One Body: An Essay in Christian Sexual Ethics (Notre Dame University Press), and Actuality, Possibility and Worlds (Continuum). His research areas include metaphysics, philosophy of religion, Christian ethics, philosophy of mathematics and formal epistemology.