當然，正當之工會活動絕對有受法律保護之必要，此對於勞工團結權之維護是否能落實甚為重要。因此有關工會活動正當性之判斷基準，不論在勞工行政、司法實務上都是重要之課題。本論文以工會活動正當性之判斷基準為研究對象，以鄰國日本之學理及實務為研究範疇，從觀察日本戰後近40年之學說史，並大量閱讀日本實務案例著手，將日本工會活動正當性判斷基準之「忍受義務說」、「違法性阻卻說」以及「許諾說」進一步分析。最後，透過檢討我國不當勞動行為裁決委員會所作出之裁決決定，提出本文對於目前台灣較多引用之「忍受義務說」之疑問，嘗試建構「違法性阻卻說」在台灣實務與學理上發展之可能性。希望本論文能達成在學術上有擴展工會活動正當性判斷基準討論視野之作用，則甚幸也。
When a labor union is formed, for the purpose of organization and operation of the union and also the effort to improve terms of employment for its members, it will inevitably conduct various types of activities. Activities that advocate a union's demands or statements and demonstrate a union's influence tend to lead to conflicts with the rights of employer's property management and business management. As a result, it is necessary to resolve the question of to what extent union activities should be protected by laws.
Article 5 of the Act for Settlement of Labor-Management Disputes of the Republic of China states the definition of “dispute activities” but not “union activities”. Although union activities are protected under Article 35 of the Labor Union Act, however, what activity is qualified for the protection of the Article is not established clearly anywhere in the substantive law of the Republic of China. Therefore, resolving disputes between employees and employers arising from the conflicts between union activities and the employer's rights or from disobeying employer's instructions is one of the important issues to be explored in academia.
Legitimate union activities must be protected by law. It follows that effective protection of the right of workers to organize is crucial. Hence, the criteria to determine the legitimacy of any union activities represent an important topic on labor administration as well as judicial practice. This thesis explores the justifications of union activities, the scope of the study is the theories and practice in the neighboring country, Japan. The study has been conducted by observing the theories developed in Japan over the almost-forty years after the Second World War. In addition, a large number of case studies have been processed for a further analysis of the criteria to determine the legitimacy of any union activities in Japan. Finally, the study has examined the decisions of the Board for Decision on the Unfair Labor Practices, and presented questions regarding the more frequently cited theory of "duty of toleration" in Taiwan and attempted to analyze the feasibility of developing the theory of "illegality deterrence" in both academic theory and legal practice in Taiwan. The aim of this thesis is to broaden the academic horizon with respect to the criteria to determine the legitimacy of union activities.
