The book is rich in the scholarly interpretation of the doctrine of the Upanisads and their bearings on Buddhism. It describes how the idea of Supreme being was conceived in the words of Brahman and Atman and how these two entities merged with each other and became identical. It also discusses the doctrine of metempsychosis and the development of thought of Indian Philosophy from an impersonal god to personal god. In the end it discusses the Doctrine of Buddhism.