Swami Tattwamayananda’s exposition of the TAITTIRIYA UPANISHAD was given at the Lake Tahoe Retreat run by the Vedanta Society of Northern California, San Francisco (founded by Swami Vivekananda in 1900) from July 27, 2019, to August 4, 2019, in a series of 9 lectures. The Taittiriya Upanisad comprise the 7th, 8th, and 9th chapters of the larger Taittiriya Aranyaka that belongs to the Yajur Veda tradition. The Upanishad contains 31 anuvakas (lessons): 12 in the Siksa-valli, 9 in the Ananda-valli, and 10 in the Bhrigu-valli. Sri Shankaracharya’s (788-820 CE) commented on the Taittiriya Upanishad and “the fact that he cited from it 147 times in his Brahma-Sutra-Bhashya speaks volumes for its authoritativeness.” (Sarvananda, Taittiriyopanishad 5) Before Sri Shankaracharya, the idea of Advaita or nondualistic philosophy existed because it is as old as Rig Veda itself, but the formulation of a complete and compact philosophical structure, expounding its metaphysics, ontology, cosmology, logic, and epistemology, was entirely his contribution.Swami Tattwamayananda, currently the Minister of the Vedanta Society of Northern California, San Francisco, (originally founded by Swami Vivekananda in 1900) served in various centers of the Ramakrishna Order in India as editor, publisher, and teacher of Sanskrit, Advaitic texts such as Sri Shankaracharya's commentaries on the 'Prasthanatraya' (the fundamental Sanskrit texts of Vedanta philosophy), Buddhism and Indian philosophy. He underwent traditional training in Hindu scriptures, Sanskrit, Vedic and Vedantic literature for many years, from his early days. Before coming to the United States in January 2012 he was teaching Sanskrit, Vedantic scriptures and Indian philosophy at the Training center in Belur Math, the institution that trains the monks of the Ramakrishna Order at the headquarters of the Ramakrishna Mission, Kolkata, India. Apart from his traditional education, the Swami has also received modern University education in English literature, psychology, European history, and Western philosophy. He is frequently invited for lectures on Yoga, Vedanta, and traditional Hindu scriptures and for participating in interfaith dialogues.For more:Web: www.sfvedanta.orgLivestream: https://livestream.com/sfvedantaFacebook: www.facebook.com/sfvedantaYouTube: https://www.youtube.com/user/SFVedantaAll Original Content © Vedanta Society of Northern CaliforniaWorks Cited:Sarvananda, Swami. Taittiriyopanishad. Sri Ramakrishna Math, Mylapore, Chennai-4, 2015.