Sri Aurobindo and the Mother are regarded as the architects of Integral Yoga or "Purnayoga," which is the process of seeking union with the Divine while increasingly manifesting such divine nature within and without. The book argues that Sri Ramakrishna and Swami Vivekananda laid the conceptual and practical foundations of Integral Yoga before Sri Aurobindo and the Mother took it to its fruition. To this end, a comprehensive comparison of the works of Sri Ramakrishna and Swami Vivekananda with the works of Sri Aurobindo is offered, including an examination of both convergences and divergences, specifically focused on some of the features of Integral Yoga. It shows how Sri Aurobindo's ideas can be understood as an extension of the thoughts of Sri Ramakrishna and Swami Vivekananda, and discusses the presence of the evolutionary thread of the progression of integral thought from Sri Ramakrishna to Swami Vivekananda to Sri Aurobindo. It also explores the historical connection between Sri Ramakrishna, Swami Vivekananda, and Sri Aurobindo, and critically examines the teachings of Sri Ramakrishna and Swami Vivekananda in the light of Sri Aurobindo's vision.