India · fl. c. 8th c. BCE (traditional)
Uddālaka Āruṇi
Upanishadic teacher who told his son ‘You are that’
In the Chāndogya Upaniṣad he teaches his son Śvetaketu, with images like salt dissolved in water, that the subtle essence of all things is the self: ‘you are that’ (tat tvam asi). He also held that the world arose from ‘being’ (sat), not from non-being.
Life and thought
Uddālaka Āruṇi is one of the two most quoted teachers of the early Upanishads, a Brahmin of the Kuru-Pañcāla country of northern India, perhaps of the 8th century BCE. Nothing about him is known outside these texts, where he appears as a learned ritualist, as the teacher of his son Śvetaketu and, in the Vedic lineages, of Yājñavalkya, who later bested him in debate.
His most famous lesson, in the sixth chapter of the Chāndogya Upaniṣad, is a series of thought experiments. Dissolve salt in water: you cannot see it, yet every sip tastes of salt. Split a banyan seed: you find nothing, yet from that subtle nothing a great tree grows. So, he says, one fine essence pervades everything, and “that is the self—you are that” (tat tvam asi). Against those who said the world began from non-being, he held that it came from being (sat). Śaṅkara later made “you are that” one of Advaita’s great sayings.
Works
Students
fl. c. 8th–7th c. BCE (traditional)YājñavalkyaThe Upanishadic teacher lists name Yājñavalkya as Uddālaka’s pupil, though they also clash in debate.Shaped
c. 700–750 (older scholarship: 788–820)ŚaṅkaraUddālaka’s ‘tat tvam asi’ became one of Advaita’s ‘great sayings’ (mahāvākyas).On the record
The Upanishadic teacher lists name Yājñavalkya as Uddālaka’s pupil, though they also clash in debate.
Macdonell and Keith’s Vedic Index, cited by Wikipedia, makes Yājñavalkya the pupil of Uddālaka Āruṇi, whom he later defeats at King Janaka’s court. Other traditions name Vaiśampāyana as his teacher in the Yajurveda. Nothing is known of either man’s dates; the Bṛhadāraṇyaka Upaniṣad is dated c. 700 BCE.
Sources: Wikipedia, “Yajnavalkya” (citing Macdonell & Keith, Vedic Index)