The term Vedanta means the end of the Vedas and could refer to the Upanishads that form the latter portion of the Vedas. It is so called because it teaches the ultimate aim and scope of the Vedas — to realise the Supreme Brahman. The wealth of wisdom contained in Vedanta Sastra is not spelt out explicitly and philosophers have been trying to unravel its true import, said Sri Mani Dravid Sastrigal in a lecture.
In the text Brahma Siddhi, believed to be composed by Mandana Misra, the essence of Advaita Tatva — the non-dualistic aspect of Vedanta — is discussed. This text accepts the authority of the Vedas as proof and source of knowledge, lays down the arguments and counter-arguments. It then reconciles the various perspectives and harmonises them to arrive at the conclusion of “the identity of the Self with the Supreme Brahman and of the absolute reality of the one and only existence.”
We all know that we exist. We are aware of our consciousness. But what is the nature of this consciousness, this existence? By using our sense of discrimination, we can know that the notions founded on ego are not the fundamental reality. There is something beyond it. What is it? How is the realisation of Brahman achieved? When the Vedas describe Brahman, they say He is beyond the reach of words and their meanings. If this is so, how is it possible to know the Brahman? Perception and inference are the two sources of knowledge that the human mind can access. But on the spiritual plane, with reference to the knowledge of Brahman, perception has to transcend the senses (including mind and intellect) to gain divine insight — as in the revealed scriptures, particularly the Upanishads.
The Katopanishad has this to say of the experience of Brahman: “Words cannot explain nor can human thought grasp its nature. Eyes cannot see Him.” To the question how else can one comprehend Him, it says we can only go by the experience of those seers who have realised Him in their inner consciousness. These enlightened sages say the experience of Brahman is one of peace, eternal effulgence and absence of activity, and it is possible to experience this when the mind is pure and tranquil.