When one receives an endowment, sound fiscal policy dictates that only the interest from the principal be used. A prudent manager of the endowment would invest at least a portion of the interest back into the endowment principal in order to increase the holdings and the future earning potential. If, over time, the interest and a portion of the principal are spent each year, the endowment will slowly disappear and no longer be of use. The earth and its resources are our natural endowment. For centuries we lived primarily off the interest, using those resources that were constantly renewed by the natural endowment. Unfortunately, we are now making major cuts into the principal, and the inheritance we are leaving future generations is significantly less than what we have received.  Our responsibility to future generations challenges us to return to a more sound ecological endowment policy.