2014年3月，由學生發動的占領立法院的運動―「太陽花學運」，不但得到社會大眾廣泛的矚目，而且也引發社會各界諸多的爭議。執政者強調民主需要法治，譴責這種違法行為是法治國家所不容；而支持者則引用「公民不服從」的概念，做為合理抗爭的依據。占領最高立法機關的行為，在一個自由民主國家可以得到證成嗎？本文以「太陽花學運」為例，探討自由主義的憲政體制中違法行為的意義和限制。由於任何一個憲政民主國家的法律或政策都不是完美的，所以可能存在合法性和正當性的差距，因此適當、有限的違法行為―公民不服從，有時候不但可以得到證成，甚至是民主政治的一個必要元素。本文透過對公民不服從的意義和證成之探討，評論「太陽花學運」的合理和不合理之處。

In March 2014, thousands of students broke into and occupied the Legislative Yuan, Taiwan’s Parliament, in protest of the non-transparent process the controversial trade agreement with China. The government condemned the sit-in, later named the “Sunflower Student Movement,” as illegal and should not be allowed in a democratic society, while the movement supporters argued that it is legitimate as an act of civil disobedience. The problematic of this paper is hence to use the Sunflower Student Movement as a case study to explore the meaning and limits of illegal actions in a liberal constitutional state. No existing constitutional democratic states are perfect concerning their laws and policies. There is a significant difference between the notions of legality and legitimacy to justify the act of civil disobedience. Some adequate and constrained actions to refuse obeying certain laws can be justified sometimes. As some might argue, they are even necessary components of a mature democracy. By analyzing the definition and justification of the notion of civil disobedience, this article will evaluate the reasonableness of the Sunflower students movement.