Ｇ・ハーマン相対主義説の論理

Abstract

In this paper, I intend to make clear the logical structure which enables Gilbert Harman to make his theory of moral relativity consistent as a whole. On the basis of the theory of moral conventions, which are maintained through continual tacit bargaining and adjustment, Harman explains relativistic aspects each person's moral framework has. In his recent works, thus, the theory of moral conventions is introduced as the one which is able to explain actual moral diversity and other phenomena concerning morality more appropriately than any other theories, including those of moral absolutism. On the other hand, however, this theory is also accepted from a naturalistic kind of view Harman seems to have kept. He thinks that, in order to prevent moral theories from degenerating into moral psychology, it must be possible to give our intuitive moral judgments attained through observations the explanations made in the way similar to science. To attain this, then, the theory of moral conventions is required which implies a thesis that the reasons for each person to act morally stem from his or her affective attitudes. As a result, Harman's theory of moral relativity includes two sorts of metaethical theories about moral features, the one is called a "theory of practical reasoning, " the other often called an "impartial spectator theory." Each of them, further, can be understood as theories about the truth of moral judgments which can describe moral facts.