Theories of one ultimate reality exist in philosophies of both the East and the West, and in both traditions such theories are commonly connected with religion. In Religion and the One, Frederick Copleston explores the approach that different philosophies have taken to the question of divine reality, with a special focus on the metaphysics of the One.In the first part of the book, Copleston looks at the features of different traditions, discussing Taoist philosophy, the Vedanta schools of thought in India, the development of philosophy in the Islamic world, and a number of movements from the Western tradition. The second part questions why people form such theories, exploring factors such as the nature of the self and the cognitive value of mysticism.Writing with all his hallmark learning and lucidity, the author also discusses the consequences of the metaphysics of the One for ethical ideals and social activism. Approaching the issues in an open-minded and unprejudiced fashion, he does not pretend to have answers to all the questions he raises. However, unlike many theologians and philosophers, he is not prepared to dismiss metaphysics as being inherently irreligious.