broad categories of reasons for caring about biodiversity, we have lumped motivations that derive from different understandings of the facts and different perceptions of the good.
Motivations rooted in claims of usefulness and satisfaction of human preferences are recognized in Western philosophical systems, but there is sharp disagreement on how much weight should be accorded to such motivations. Usefulness, especially, depends on claims of fact, and there remains much dispute about many of the pertinent facts. When it comes to motivations based on aesthetics and moral duty, alternative philosophical systems differ as to how much weight such motivations should be accorded and as to the ethical foundations on which the motivations are based.
It is no wonder that the public discussion of biodiversity issues is so extraordinarily susceptible to semantic confusion and talking at cross purposes. The objective of this chapter is to bring clarity to the discussion by characterizing the main traditions of Western ethical theory and developing briefly their implications for biodiversity.
Consequentialism holds that right action is whatever produces good consequences. For consequentialists, practical ethics involves judging the consequences by possible actions. People might be inclined to differ about which of consequences are most important. To put consequentialism into action, a single scale for evaluating quite diverse consequences would be useful.
Utilitarianism provides such a scale. Its basic premise is that whatever an individual wants is the best indicator of what is good for that individual. The consequences of different actions can be judged on a single scale: their contribution to preference satisfaction.
To modern utilitarians, preferences summarize whatever motivations lead the individual to prefer one option to another and, given the opportunity, to choose the preferred option. It is a misconception to claim that utilitarianism counts only the satisfaction of instrumental needs (food and shelter, for example) and the selfish desires of individuals. Preferences might concern the public good and community values and might be the results of a long and searching process of introspection. An individual's preferences might well be the considered plan for a thoroughly examined life, but nothing requires that they be. In deference to individual autonomy, utilitarianism does not subject preferences to interpersonal review or to substantive tests against principle or reason.
The individual's preference (or utility function) makes different options commensurable on the scale of preference satisfaction. The individual can adjust the bundle of goods and services chosen, making tradeoffs at the margin to maximize preference satisfaction. Given the budget constraint, individual willingness to