Verily, in whom unwisdom is destroyed by the wisdom of the Self, in them, Wisdom, shining as the Sun, reveals the Supreme.—Bhagavad Gita. Yoga is a subject which has enthralled the attention of the world from time out of mind. No one has hitherto done justice to such a grand system though there have been, now and then, innumerable attempts. The present author, my esteemed friend, Swami Mukerji, a Yogi who comes out of a successive generation of Yogis, is a fit and proper instrument to handle the subject. He, in these lessons prepares the layman for an understanding of the Yoga and, through a series of wise and masterful sayings, impresses on the mind of the reader the necessity for rising above materialism, nay, solves the very problem "What am I?" Every line is pregnant with mature thoughts and rivets one's attention, and makes him think, think, think. This is not a work for which an introduction, briefly setting forth the contents, could be written. I can but ask you to read, digest and improve.