Tom Regan has made a very important contribution to the debate on environmental ethics in his “On the Nature and Possibility of an Environmental Ethic.” The debate can be brought out yet more clearly by contrasting Regan’s views with those of an eminent critic of environmental ethics in Regan’s sense, William K. Frankena. I argue that Regan’s position has much to recommend it, but has a fatal flaw whichwould render environmental ethics unjustifiable. I suggest this flaw can be remedied by divorcing an environmental ethic from a dubious ontological commitment. Reflection on metaethics, ontological commitments, and the nature of ethical justification leads to a conclusion favorable to an environmental ethic.

In Kant’s philosophy nonrational beings are denied moral standing. I argue that Kant's rational humanism is arbitrary and morally impoverished. In particular I show that Kant moves illegitimately from the first formulation of the categorical imperative (which makes no mention of a moral domain) to the second (which limits moral recognition to rational beings). The move to the second fonnulation relies on a new and unsupported principle introduced by Kant: rational nature and only rational nature exists as an end in itself.