The Macmillan Encyclopedia of Death and Dying is a contribution to the understanding of life. Scientists and poets have long recognized that life and death are so intimately entwined that knowledge of one requires knowledge of the other. The Old Testament observes that ''all flesh is as grass.'' Religions have addressed the question of how one should live with the awareness of inevitable death. Often the answer has been based upon the vision of a life beyond death. Societies have developed systems of belief and practice to help their people cope with the prospect of death and the sorrow of grief. Children are often puzzled by the curious fact that flowers fade and animals stop moving. This incipient realization of mortality eventually becomes a significant part of the adult's world-view in which hope contests with fear, and faith with doubt.