The first part of this study is devoted to analysing the prevailing western ethical systems and to a comparison of them with a conception of a new environmental ethics. The author here, with reference to J. Passmore, divides the western approach into a “dominant tradition”, in which man conducts himself with regard to the things of nature, and to nature itself, as a tyrannical ruler, and the less widespread tradition of man as superintendent (or supervisor), and man as perfecter. According to Sylvan, environmental ethics is in conflict with each of these conceptions. The second part of Sylvan’s text introduces thought-experiments which demonstrate the inconsistency of the environmental tradition of western ethics based on (human) chauvinism. First of he introduces the thought-experiment of “the last man” and then the thought-experiment of “the last people”, “the great businessman” and “the disappearing species”. The third part of Sylvan’s text then briefly considers the possible consequences connected with the acceptance of an environmentally-ethical attitude. This brings with it, in Sylvan’s view, changes to one’s ethical conception and changes to meta-ethics. New concepts are needed to treat old and new realities; a fundamental change in perspective is required.