This book is based on the notes of weekly lectures given by Swami Yatiswarananda at Ramakrishna Math, Bangalore. The Swami, a Vice-President of the Ramakrishna Order, was an illustrious disciple of Swami Brahmananda. He was a well-known spiritual figure in the Neo-Vedanta movement and did 17 years of pioneering work (1933-1950) in spreading Vedanta in Europe and USA.
Change is always subjective. All through evolution you find that the conquest of nature comes by change in the subject. Apply this to religion and morality, and you will find that the conquest of evil comes by the change in the subjective alone. That is how the Advaitic system gets its whole force, on the subjective side of man.
-Swami Vivekananda