In this book, Leif DeVaney brings the traditional philosophical branches of metaphysics and ethics to bear on conservation biology. While many previous attempts at asking and answering ethical questions related to conservation and other environmentally relevant activities exist, few such attempts have engaged adequately with the “rock bottom� approach of metaphysics. Through this metaphysically realistic lens, the ontological status of the population (as well as other ecological “wholes�) is challenged. DeVaney argues that individual nonhuman animals are found to have interests that parallel human interests. These include the biotic goals of survival and reproduction, as well as freedom from undue pain and suffering. From an ethical standpoint, the conclusion differs drastically from the dominant consequentialist contention that the good of some can be sacrificed for the supposed greater good of the many. DeVaney initiates the establishment of the  subdiscipline of conservation metaphysics, which naturally leads to a theoretically grounded ethic.