If environmentalists are to combat effectively the continuing environmental decay resulting from more and more intense human exploitation of nature, they need a plausible and coherent rationale for preserving sensitive areas and other species. This need is illustrated by reference to two examples of controversies concerning large public projects in wilderness areas. Analyses of costs and benefits to presently existing human beings and the utilitarian theory which supports such theories are inadequate to provide such a rationale, as other writers have shown. A number of environmentalists have suggested that ascriptions of rights to nonhuman animals, plants, and other natural objects may provide the necessary rationale. I argue that such ascriptions can only be effective if they are supported by a general theory of rights. Although no such general theory is developed, I state four minimal conditions which must be fulfilled by all rights holders as entailments of the concept of a right and, hence, as necessary conditions on rights holding, regardless of the general theory of rights espoused. I then argue that no appeals to rights of nonhumans can simultaneously fulfill these four minimal conditions and, on the other hand, satisfy the need for a coherent rationale for environmental preservation. In the central argument of the essay I exploit the distinction between the concern of vegetarians and antivivisectionists who rest their case for animal rights on the analogy of animal suffering to human suffering and the concern of environmentalists to protect the integrity of holistic ecosystems. I then conclude that even if the case for nonhuman rights can be made convincingly, the rights defended are insufficient for the development of a complete and coherent rationale for environmental preservation.
