The volume in hand is the upshot of Shri Anirvan's talks on the Svetasvatara Upanisad at a Dharmasabha held in Kolkata during 1 September 1968 to 23 March 1969. The Svetasvatara Upanisad contains 113 mantras or slokas (sacred verses) in six chapters(adhyayas). The important distinction of this Upanisad lies in the fact that it is composed with respect to a particular cult - Rudra cult - prevalent during the pre- and post- Vedic period. Therefore, it is also called a Rudra Upanisad. The Rudra cult, of late, turned into the Yoga cult, as its main focus. The Svetasvatara is not amongst the older Upanisads. It is definitely composed after Panini. In this Upanisad, we find the Vedantic-Upanisadic Brahmaveda, Vedic and Puranic Devavada, and the Yogavada of the Samkhyas meeting in a confluence (triveni sangama) of the three mainstream philosophical religious traditions of India.