A compilation of letters written by Sri Aurobindo to disciples during the 1930s, this book presents the major aspects of his spiritual teaching. The first parts deal with the psychological and philosophical foundations of his teaching and relate them to other systems of yoga and philosophy. The next sections deal with the method of practice, starting with the bases of yoga and continuing with the different types of sadhana, descriptions of experiences and realisations, the triple transformation that defines the essence of the yoga, and the difficulties in transforming the nature. A glossary of the terminology used by Sri Aurobindo completes the volume.\n\n