The history of Indian yoga is a most fascinating chapter in the larger history of man's highest endeavours to exceed manhood and to hew new paths of evolving the next species. This volume concentrates on the theme of the synthesis of yoga, and dwells principally of five systems of the synthesis of yoga: the very first synthesis of yoga is to be found in the Vedic Samhitas, -the earliest records of human civilization. The yoga of the Gita, which comes next, is eminently the synthesis of the paths of knowledge, action and devotion. The fourth synthesis is to be found in Tantra. The latest synthesis of yoga which draws from all previous systems of yoga, presents a new departure both in its objectives and methods. This is the synthesis of yoga of Sri Aurobindo and the Mother, which has worked out, with scientific rigour the processes of ascent to the Supermind as also of the descent of the Supermind on the Earth,-the processes that are new and indispensable for the synthesis of Matter and Spirit and for the evolution of the Supramental Divine Body, which will mark a revolutionary change in the very processes of evolution and establish a new mode of Supramental action capable of creating on the Earth the fulfillment of the ideals of light, freedom, bliss and immortality. Science and Spirituality meet in a natural synthesis in the yoga and it provides a solution to the contemporary crisis. It is this theme that imparts to this volume its special relevance. Pursuit of yoga is a living tradition in India, and it is this pursuit which provides to Indian culture its perennial spiritual essence. This volume while dwelling on the theme of the synthesis of yoga takes us to those realms of spiritual consciousness by the cultivation of which humanity can arrive at the art and science of collective practice of spiritual fraternity that is indispensable for everlasting peace and harmony on the Earth.