Summary: The Aurobindo Birth Centenary Library, Volume 22, explores the evolution of consciousness from the material to the spiritual plane in Indian history. The Vedic mystics sought spiritual truths through inner sight and hearing, leading to a descent of the universal consciousness into matter and the development of philosophies and yoga processes. The text discusses the importance of spiritual experience over intellectual thought in yoga, emphasizing the need for inner transformation and the pursuit of the Divine in all aspects of life. It addresses the limitations of the intellect in understanding spiritual truths, highlighting the importance of personal experience in realizing the unity of all knowledge. The text also delves into the complexities of integrating the spiritual and material worlds, emphasizing the necessity of inner growth and the pursuit of spiritual consciousness to bring about change in the outer world.