In What Is God?, Kevin Vost (Memorize the Reasons!) shows you how you can better know the most worthy object of our love, following the thought of the great theologian who first asked that question as a young boy: St. Thomas Aquinas. That thirteenth-century Dominican friar later devoted much of his masterwork, the Summa Theologica, to exploring God in his deepest essence. But if you don't have time to read a 1.8-million-word philosophical treatise translated from medieval Latin, Dr. Vost is here to break down the key parts for you. In clear and approachable fashion, What Is God examines God's attributes and considers questions about him that have vexed mankind for centuries. What does it mean for God to be simple? To be perfect? Is God really knowable, after all? Is God able to change the past, or cause it not to have been? And the classic: Can God make a boulder so big that even he cannot lift it? St. Thomas has an answer for all of these, and more . . . and What Is God? is the first book to collect and explain those answers in one place for modern readers.