Commercial speech is like obscenity... we can't seem to define it, but we know it when we see it.
What Brahman is cannot be described. All things in the world? the Vedas, the Puranas, the Tantras, the six systems of philosophy? have been defiled, like food that has been touched by the tongue, for they have been read or uttered by the tongue. Only one thing has not been defiled in this way, and that is Brahman. No one has ever been able to say what Brahman is.
The more aware we are of our basic paradigms, maps, or assumptions, and the extent to which we have been influenced by our experience, the more we can take responsibility for those paradigms, examine them, test them against reality, listen to others and be open to their perceptions, thereby getting a larger picture and a far more objective view.