If ultimate reality is beyond language, how can language comprise the only valid method of acquiring knowledge of it? And if no language whatsoever can describe ultimate reality, what guarantee could there be that what Vedic language purports to disclose is anything other than a chimera? These are problems that lie at the heart of Shankara’s Advaita Vedanta, but occur, in different guises, in a wide range of religious traditions. They are problems which raise questions about text and interpretation, about ‘revelation’ and the ways in which language is held to work. They require us to reflect on how we know what we know. They challenge us to define in what senses, if any, the ultimate may be said to be ineffable. In this lecture, I shall re-examine the work of the famous Indian non-dual commentator, Shankara (c.700 A.D.), who held that ultimate reality (brahman) is beyond language and who frankly admitted that the Veda has no authority once brahman is known. I shall, however, challenge interpretations of his work which assume that language is inadequate to its task and so locate knowledge of the ineffable either in some kind of mystical experience or in the secondary or poetic use of language. I shall argue that, in Shankara’s view, the language of the Upanishadic Vedic texts is precisely adequate to its task, given the epistemological and hermeneutical strategies the Veda provides for the Advaitin commentator to deploy.