Yoga is an exact science. It aims at the harmonious development of the body, the mind and the soul. Yoga bestows perfection, peace and eternal bliss. The path of Vedanta is the most natural. It is nothing but manifesting what you exactly are in essence. It is mainly through books that we establish a connection with and obtain the fruits of a great mind's lofty labours. This avenue is open to all. In their books the Great Ones present themselves before you, talk to you, giving you the most pre-cious thoughts and ideas and pouring their souls into you. The present book is a collection of lectures given by Sri Swami Sivananda on different occasions.