Book excerpt: The Upanishads are a group of texts in Hindu sacred literature that are considered to reveal the ultimate truth and whose knowledge is considered to lead to spiritual emancipation. In the Upanishads, we find the finest flowering of the Indian metaphysical and speculative thought. They are utterances of seers who spoke out of the fullness of their illumined experience. Upanishad is derived from upa (near), ni (down) and sad (to sit). Hence, the term implies the pupils, intent on learning, sitting near the teacher to acquire knowledge and truth. There are over 200 Upanishads but the traditional number is 108. Of them, only 10 are the principal Upanishads: Isha, Kena, Katha, Prashan, Mundaka, Mandukya, Tattiriya, Aitareya, Chhandogya and Brihadaranyaka. This book is a forerunner in introducing these primary Upanishads to the uninitiated.