Monotheism is usually considered Judaism's greatest contribution to world culture, but it is far from clear what monotheism is. This work examines the notion that monotheism is not so much a claim about the number of God as a claim about the nature of God. Seeskin argues that the idea of a God who is separate from his creation and unique is not just an abstraction but a suitable basis for worship. He examines this conclusion in the contexts of prayer, creation, sabbath observance, repentance, religious freedom and love of God. Maimonides plays a central role in the argument both because of his importance to Jewish self-understanding and because he deals with the question of how philosophic ideas are embodied in religious ritual.