Thomas Berry explores the meaning of work from the standpoint of human civilization responding to the call of the universe, replacing use and exploitation of nature with the wonder, rapport, and intimacy so important to the psychic balance of the developing human and natural harmony of life on Earth. The Great Work is defined as the work of thousands upon thousands of humans who recognize how to be present to the universe and reverse the tragic misuse of our natural environment. [Reprinted from "The NAMTA Journal," 26,1 (2001 Winter): p156-167. This talk was presented at the NAMTA conference titled "Celebrating Montessori's Great Work: Our Gift for the Future," Cleveland, Ohio, October 5-8, 2000.]