St Thomas Aquinas (1225-1274) saw religion as part of the natural human propensity to worship. His ability to recognize the naturalness of this phenomenon and simultaneously to go beyond it, to explore spiritual revelation, makes his work fresh and highly readable today. While drawing on a strong distinction between theology and philosophy, Aquinas interleaved them intricately in his writings, which range from an examination of the structures of thought to the concept of God as the end of all things. This accessible new translation chooses substantial passages not only from the indispensable Summa Theologicae, but from many other works, fully illustrating the breadth and progression of Aquinas's philosophy.