Borderlands: Human conduct at the limits of ethics.

This dissertation examines two main problems: (1) the identity of beings with moral standing and (2) the adjudication of conflicts arising between beings with moral standing. Solving (1) provides a vehicle for treating (2). Various features of beings identify them as having different kinds of moral standing. These varieties of standing correspond to varying degrees of moral value, establishing a hierarchy of moral priority. Conflicts between beings with moral standing are then adjudicated in favor of the party to the conflict who has the most or weightiest moral value. Moral agents have the weightiest moral value in virtue of their cognitive and affective capacities. Nonhuman mammalian species have a lesser degree of moral value since they lack the cognitive capacities of agents but share their affective capacities. Birds, reptiles, and fish have even less moral value because they have only sentience. Finally, the weakest degree of moral value is had by nonconscious beings, notably plants, which have only a good-of-their-own. Natural objects and artifacts have no moral value at all since they have no cognitive or affective capacities, and no good-of-their-own. Even though moral agents are more valuable from the moral point of view than any other being with moral standing, this does not mean that the interests or good of agents always take precedence over the interests or good of other, nonhuman beings. It is only on those occasions where the basic welfare interests of agents are at stake that a conflict between human and nonhuman beings is resolved in favor of moral agents. In situations where the welfare interests of agents are not at stake--though other non-basic interests may be--while the welfare interests or basic good of nonhumans are at stake, the conflict is adjudicated in favor of the nonhumans