This is the first book of Swami Vivekananda's complete works. This is no less than a work of a PhD. He doesn't just preach in the terms of philosophy, he quotes them with physical, meta physical, scientific reasoning, he discusses it with objectivity and proves them with the support of facts like our maths theorems.. he talks about infinity, abstractness, void, energy, matter, mind and the coherence between them. This is eye opener...he knows the history of the topic, every topic he chooses to discuss about, he takes you on a tour from its origin, into its steps of evolution ...the various forms it took... but he doesn't force you to accept anything blindly..he leaves you to try it out. In this first book he barely scratches the surface of religion and its universal nature.. he traces out the patterns between Hinduism, Islam, Christianity, Buddhism, Zoroastrian thought processes.. their ways of life and beliefs. He introduces you to some of the concepts of Vedas and Upanishads and various techniques adopted by them. Irrespective of what religion, caste, race or belief you belong, this book will give you an insight to the world of religions and will take you through an exhilarating journey on the conquest of mastering the self and the divinity within each of us.