This title focuses on Polkinghorne's theory that science and religion are two aspects of the same world.

Both science and religion explore aspects of reality, providing "a basis for their mutual interaction as they present their different perspectives onto the one world of existent reality," Polkinghorne argues. In One World he develops his thesis through an examination of the nature of science, the nature of the physical world, the character of theology, and the modes of thought in science and theology. He identifies "points of interaction" and points of potential conflict between science and religion. Along the way, he discusses creation, determinism, prayer, miracles, and future life, and he explains his rejection of scientific reductionism and his defense of natural theology.

The book is published by Templeton Press.