著名的亞理士多德學者大衛．羅斯 (Sir David Ross, 1877-1971)在當代倫理學上是一個「義務論者」(Deontologist)，主張吾人之遵守道德是做人的責任，而非為了任何功利或效益——此一思想，近於漢儒董仲舒的「正其誼不謀其利，明其道不計其功。」 本文將依據他的主要著作《正確與良善》(The Right and the Good, 1930) 和《倫理學的基礎》(Foundations of Ethics, 1939)，來探討其在當代倫理學裏頗為重要的概念「初適責任」(Prima Facie Duty) 。本文之敘述，將以「由小而大」的方式，首先詮釋羅斯所主張的「初適責任」的意義，並列出其種類，然後探討他的道德理論，最後談論羅斯在當代倫理學的地位。

The well-known Aristotelian scholar Sir David Ross (1877-1971) is a Deontologist in contemporary ethics. He claims that the observance of morality is one's responsibility as a human being, not for any utility or effect. Such a concept is similar to the idea of Dong Zhongshu, a preeminent Confucian in the Han Dynasty--“Doing the right thing without utilitarian considerations.” This paper is based on Ross's major works, The Right and the Good (1930) and Foundations of Ethics (1939), discussing the most important concepts of his moral theory--Prima Facie Duty. The argument of this article will first interpret the meaning of Prima Facie Duty, then discuss his moral theory, and finally talk about Ross's role in contemporary ethics.