以「正反討論處理公共爭議」作為課程進行方式，是否是一種好的教學途徑？這種方式可能會動搖學生既有的道德信念以及加深同學們相對主義甚至虛無主義的道德觀。本文則試圖為這種「動搖信念」以及「相對主義」的指責提出反駁。首先指出「動搖信念」，事實上有助於糾正錯誤、加強認識、更能貼近真理等優點。而正反討論是否會惡化相對主義觀點，本文則認為正反討論也可以著眼於努力追求最佳正確判斷，並不必然反應相對主義觀點。此外，透過聆聽對方論點，也是一種同理心、相互瞭解、尊重的展現，這是朝向解決問題的開端，也不是只求各說各話而已。本文並藉由課堂問卷與上課經驗，希望對於此一教學方式提供實務上的經驗分享，並附加說明此種教學方式需注意之處。

Is it a good way to teach by discussing a controversial issue with pro and con arguments? This way might shake the original moral beliefs and promote the ideology of relativism and nihilism of students. This paper tries to defend against the above critics. First, I will point out that so-called shaking beliefs in fact help to correct errors, better understanding and approach the truth closer. Second, whether the pro and con arguments might lead to relativism or nihilism. I contend that this way might aim to focus on the truth but through different ways. Furthermore, while we listen to different points of view, we respect their thinking, opinions and try to empathy others. This is a beginning to solve the difference. In addition, this paper also uses survey to collect the response of students and their comments and hope to make the pro and con arguments to be a good way of teaching.