Aruni

Uddālaka Āruṇi, commonly called Aruni or Uddalaka, was a Vedic sage and teacher of ancient northern India and one of the most frequently named figures in the early Upaniṣads. He is especially associated with the Chāndogya Upaniṣad, whose sixth chapter presents him instructing his son Śvetaketu in the identity of the individual self (ātman) with the ultimate reality (brahman), summed up in the mahāvākya “tat tvam asi” (“thou art that”). He also appears in the Bṛhadāraṇyaka Upaniṣad and other early Upaniṣadic texts as a respected interlocutor on the nature of the self, the vital breaths, sleep, and death. No contemporary inscription or chronicle records his birth or death; scholarly discussion places the milieu of these texts, and thus of teachers such as Uddālaka, in the first half of the first millennium BCE, often roughly the eighth to seventh centuries BCE, without a verifiable calendar year.

Later epic tradition, above all the Mahābhārata, supplies a disciple-story that explains his name. As a pupil of the sage Ayoda Dhaumya, Aruni is said to have lain down in a breach in a flooded field to hold back the water until his teacher came, and to have been thereafter called Uddālaka. The same tradition links him with the Pañcāla country of the northern Ganges plain. These narratives belong to a later layer than the oldest Upaniṣadic passages and cannot be treated as datable biography, but they are the principal source for his traditional image as a devoted student who became a householder-teacher.

Uddālaka is portrayed as a married householder rather than a lifelong celibate. The Chāndogya Upaniṣad makes Śvetaketu his son and chief pupil. Epic accounts further give him a daughter, Sujātā, who married his disciple Kahoda; their son was the sage Aṣṭāvakra. His wife’s name is not securely attested in the early sources. He is not a Christian saint, held no papal or patriarchal office, and has no feast day, canonization, or list of patronages in the ecclesiastical sense.

His lasting importance is philosophical. In the Chāndogya teaching he uses ordinary illustrations—salt dissolved in water, the seed of a nyagrodha tree, the sap of a fig—to argue that an unseen subtle essence underlies the visible world and that this essence is identical with the self. He is also associated with a critical stance toward purely ritual learning when it is not joined to insight into that underlying reality. Later Vedānta, especially Advaita, looks back to these passages, and to “tat tvam asi,” as foundational scripture. Beyond that doctrinal afterlife, the historical person remains known only through these layered textual traditions, without recoverable dates, cities of birth or death, or a burial place.