ARE ZOOS MORALLY DEFENSIBLE?1 Tom Regan Despite important differences, a number of recent tendencies in ethical theory are united in the challenges they pose for well-entrenched human practices involving the utilization of nonhuman animals, including their use in zoos. This essay explores three such tendencies-utilitarianism, the rights view, and environmental holism-and explores their respective answers to the question, Are zoos morally defensible? Both utilitarianism and holism offer ethical theories that in principle could defend zoos, but both, it is argued, are less than adequate ethical outlooks. For reasons set forth below, the third option-the rights view-has implications that run counter to the moral acceptability of zoos, as we know them. The essay concludes not by insisting that zoos as we know them are morally indefensible but, rather, by admitting that we have yet to see an adequate ethical theory that illuminates why they are not. A great deal of recent work by moral philosophers-much of it in environmental ethics, for example, but much of it also in reference to questions about obligations to future generations and international justice-is directly relevant to the moral assessment of zoos. (Here and throughout I use the word "zoo" to refer to a professionally managed zoological institution accredited by the AZA and having a collection of live animals used for conservation, scientiic studies, public education, and public display.) Yet most of this work has been overlooked by advocates of zoological parks. Why this is so is unclear, but certainly the responsibility for this lack of communication needs to be shared. Like all other specialists, moral philosophers have a tendency to converse only among themselves, just as, like others with a shared, crowded agenda, zoo professionals have limited discretionary time, thus little time to explore current tendencies in academic disciplines like moral philosophy. The present book, bringing together, as it does, both ethicists and persons professionally involved with the real-world work of zoos, is especially noteworthy, and as beits the objectives of this book, the present essay attempts to take some modest steps in the direction of better communication between the two professions. After a brief historical section, three tendencies in contemporary moral philosophy-utilitarianism, animal rights, and holism-are described and some of their implications regarding zoos are explained. Not all these tendencies can be true in every respect (for they contradict each other at crucial places), and perhaps none is true in any. Unquestionably, however, these three tendencies are among the most important options in moral philosophy today, so that how they answer the central question I intend to explore -namely, Are zoos morally defensible ?- cannot be irrelevant to an informed moral assessment of zoos. As will become clear as we proceed, my own moral position is not that of a neutral observer. Of the three tendencies to be considered, I favor one (what I call the "rights view") and disagree rather strongly with the other two. For obvious reasons, my characterizations and assessments of these tendencies are in the nature of rough sketches; for