Although specific articles by the biologist Garrett Hardin have been frequently cited there is a lack of critical analysis of them and of his position as a whole. Hardin's position has two basic problems: it holds survival to be the ultimate value and it views mankind primarily in biological terms. These problems lead to a rejection of traditional moral values, to an inadequate view of society and to a limited view of the nature of mankind which limits morality to the members of one's tribe. Hardin emphasizes survival as a value and a biological view of man to support the assumption that present generations have an obligation to all the future generations of mankind. A critical exploration of the influence of the works of Bridgman and Schoeck on Hardin's thought clarifies his presuppositions about ethics, society and the nature of mankind. This clarification, in conjunction with an analysis of the development of Hardin's thought from "The Tragedy of the Commons" through "Carrying Capacity as an Ethical Concept", reveals the inadequacies of his position. A review of the literature on obligations to future generations, a major concern of Hardin's, provides the groundwork for a consideration of the nature of moral community and suggests that a concept of moral community can ground obligations to future generations in a manner that appreciates the importance of biology while recognizing the human transcendence of biology through culture and while maintaining traditional moral values. This dissertation argues that community is a better ultimate value than survival. Building upon Tillich's theology, an alternative which avoids the problems in Hardin's position is constructed. Hardin's and Tillich's positions are compared by considering three elements of moral community: the spatial boundaries, the temporal boundaries, and communal being. The Tillichian position furnishes a better basis than Hardin's for dealing with the question of obligations to future generations and lays the groundwork for constructing an ecological ethic.