The UpanishadsThe sacred texts of the Hindu faith The Upanishads, the earliest of which were composed in Sanskrit between 800 and 400 bce by sages and poets, form part of the Vedas the sacred and ancient scriptures that are the basis of the Hindu religion. Each Upanishad, or lesson, takes up a theme ranging from the attainment of spiritual bliss to karma and rebirth, and collectively they are meditations on life, death and immortality. The essence of their