Fr. Thomas Petri explicates St. Thomas Aquinas's understanding of God as ipsum esse subsistens (being itself), the source of all existence and goodness, and that evil is not a thing but an absence or deficiency of good within God's ultimate plan.This lecture was given on January 17th, 2025, at University of Michigan.For more information on upcoming events, visit us at thomisticinstitute.org/upcoming-eventsAbout the Speaker:Father Thomas Petri, O.P. is the President of the Pontifical Faculty of the Immaculate Conception at the Dominican House of Studies, where he also serves as an assistant professor of moral theology and pastoral studies. Ordained a priest in 2009, he holds a Doctorate in Sacred Theology from The Catholic University of America.Keywords: Aristotelianism, Causality, Evil, Free Will, Goodness, Ipsum Esse Subsistens, Pantheism, Summa Theologica, Suffering, Theology, Trinity