In the ancient wisdom texts called the Upanishads, illumined sages share flashes of insight, the results of their investigation into consciousness itself. In extraordinary visions, they have direct experience of a transcendent Reality which is the essence, or Self, of each created being. They teach that each of us, each Self, is eternal, deathless, one with the power that created the universe.

Easwaran's best-selling translation is reliable and readable. It includes an overview of the cultural and historical setting, with chapter introductions, notes, and a Sanskrit glossary. But it is...