A brimming vessel

There's not a man from whom I cannot learn no matter what his caste or his degree; there's not a voice to which I will not turn to find the knowledge that enhances me. There's not a cry by which I am not stirred, whether to action or to lethargy. I am the creature of my brother's word, Extension of his everlasting reach, the means by which my ancestors are heard, the keeper of my people's ancient speech. But for the wisdom taken without leave, I feel the burden of the need to teach -- for, as a brimming vessel, I believe the more I pour, the more I can receive.