Environmental ethics has been strongly influenced by biological ideas. This essay traces a number of these influences. Unfortunately, environmental ethicists have tended to produce moral theories on a grand scale. This tendency is criticized. It is argued that environmental ethicists should allow the ecological conception of the complexity of biological communities to influence their conception of the moral community. If this were to happen, it is argued, they would have to turn away from grand theories to 'theories of the middle (...) range' while adopting a more 'empirical' approach to moral philosophy. (shrink)