What is classical theism? In its broadest characterization, classical theism is a theological and philosophical tradition committed to a certain way of understanding the nature of God and his relationship to the world. Classical theists are united in their commitment to a single, fundamental, controlling idea: divine ultimacy. For the classical theist, God is to be conceived of first and foremost as the ultimate reality in the order of being, and the ultimate explanation of things in the order of discovery.