One of the main themes of this article is to show and analyse logical apparatus which is used for logical derivation or inference of ought-statement, or value-statements from statements of facts. Through this analysis, the traditional debate between value-fact dualism and the so called naturalism in ethics will be thrown into an entirely novel context of ethics that makes evolution of ethical system from micro-ethics to macro-ethics possible. Contemporary ecological crisis presents some new problems of ethics which can not be solved without expansion of ethical system from man to nature so that the method of this new domain of ethics (macro-ethics) will be able to attain new synthesis of value and fact.

名誉教授宮崎友愛先生記念論文集