Vedic texts, circa seventh-fifth century B.C.
The Upanishads are ancient texts written in Sanskrit, representing the religious and philosophical tradition of Hinduism and India. Together with the Aranyakas the Upanishads are found at the end of the Vedas, the sacred scriptures of Hinduism, and thus called Vedantas. Although traditionally, there are 108 Upanishads, in actuality their number is greater than two hundred if less ancient ones are included. Most scholars, however, consider ten to fifteen as the principal texts, and it is these that receive the majority of critical attention. The dates of composition of the various Upanishads cannot be determined except relatively and broadly; they are considered by followers as timeless. It is also impossible to determine who wrote the texts or how many authors were engaged in their composition. Critics believe that they were transmitted orally for centuries before being recorded in writing. The word Upanishad means to sit near, referring to the practice of a student learning at the feet of a Brahmajnani, a teacher who has become one with the Supreme Brahman. The word Upanishad may also be translated as “secret teachings,” and the contents of the Upanishads were indeed kept relatively secret until the sixteenth century, at which time they were translated into Persian and gained widespread distribution. In essence, the Upanishads state that one may achieve divinity here on earth by recognizing that one's own Atman or soul is infinite and divine. The earliest Upanishads predate Buddhism and not only influenced its development but other Asian religious traditions as well.
The oldest of the Upanishads are in prose and date from approximately the 7th century B.C. They include the Brihadaranyaka, Chandogya, Taittiriya, Aitareya, Kaushitaki, and Kena. The Kena also contains a less ancient section, written in verse. After these come later Upanishads, written in verse, circa 6th century B.C.: the Katha, Isha, and Mundaka. These were followed by more Upanishads in prose: the Prashna, Shvetasvatara, Mandukya, and Maitri.
The overriding theme of the Upanishads is the effort to become one with the supreme being, Brahman, here on earth. The only way to achieve this liberation is by giving up one's own identity and recognizing the divinity of the inner self, the Atman. This is the ultimate goal of life and leads to eternal bliss. In addition, the Upanishads also discuss the creation of the universe and the nature of karma and reincarnation. They describe the nature of Brahman and how he is everywhere and in all things in the universe; they explain that it is possible to transcend both the intellect and the senses; they teach self-control, sacrifice, and the importance of meditating and chanting the word Om; answer questions about how life becomes connected to the human form; and discuss the three stages of waking, dreaming, and dreamless sleep, followed by the fourth stage of pure consciousness.
The chief areas of critical interest in Upanishad studies are their history, philosophy, and influence. Many volumes of commentary have been published discussing the finer points of the philosophy. Paul Deussen provides an overview of the Upanishads. In his discussion of their history and significance, Deussen makes analogies to Christianity, stating that the Upanishads “are for the Veda what the New Testament is for the Bible.” He notes that both the Upanishads and the Bible stress a release from this existence—the Bible because “it is the realm of sin,” and the Veda because “it is the realm of ignorance.” Moti Lal Pandit looks into the etymology of the word Upanishad and notes the sense of urgency and competition present in the dialogues. Joel Brereton explains that the Upanishads played not only “a critical role in the history of Indic religion,” but also “still remain a major source of inspiration and authority within Hinduism.” David Frawley analyzes language and meaning and explains that the worldview present in the Upanishads is very different from that of modern times. Andrew O. Fort discusses the concept of achieving liberation on earth, as opposed to freedom after death. Rohit Mehta explains how the Upanishads are of value in modern society, indeed, that their message of wisdom is timeless. Shalini Sikka examines the influence of the Upanishads on W. B. Yeats's symbolism, while M. E. Grenander and K. S. Narayana Rao, in an essay on T. S. Eliot's The Waste Land, analyze a portion of the poem that is imbued with Hindu and Upanishadic thought.