Peter Kreeft, Ph.D., Professor of Philosophy at Boston College, is one of the most respected and prolific Christian authors of our time. His many bestselling books cover a vast array of topics in spirituality, theology, and philosophy. They include Wisdom from the Psalms, Practical Theology, Doors in the Walls of the World, How to Be Holy, Because God Is Real, You Can Understand the Bible, Angels and Demons, Heaven: The Heart's Deepest Longing, and Summa of the Summa.