Brahmanadin was an advaita teacher preceding Adi
Shankaracharya and was considered such a reputed authority on Vedanta that Adi
Shankara takes him as a source of his Advaita doctrine, not to mention the
esteem in which he was held by non-Advaitic Vedantins like Ramanuja, who also
quotes Brahmanadin.
Brahmanadin was famous as the author of Vakya, a work on the
meaning of Chandogya Upanishad. Though his work is not available, it is quoted
to clinch the issues in the works of Advaitins and by Ramanuja in his writings.
Brahmanadin holds that the formless reality (Brahman) takes
on forms for the sake of the devotees. However, this form is just only apparent
and is not real. Brahmanadin formulates the theory of the degrees of reality
like pratibhasika (merely illusory), vyavaharika (the empirical) and
paramarthika (the real).
Brahmanadin has phrased the great identity text “That Thou
Art” in the form of an aphorism: siddham tunivartakatvat, making it clear that
one’s own nature as Brahman is forgotten and is to be restored by reminders
through the teacher’s instruction.
Draviacharya, the commentator on Brahmanadin’s Vakya, has
brought out the meaning of the above aphorism by the story of a prince abducted
by dacoits as a child, forgetting his princehood. He is only to be reminded of
his true identity. This story has been used by the later Advaita thinkers as
the text of identity.