我國憲法第十一條規定「人民有言論、講學、著作及出版之自由」。其中尤以言論自由乃屬於表現意見自由之首要，廣義之言論自由更涵括講學、著作，及出版等自由。美國憲法增修條文第一條甚至開宗明義規定「國會不得制定剝奪言論自由之法律」。以言論自由之意義及功能而言，我國自行憲以來大法官在憲法解釋文中均多次加以強調。例如釋字五○九號解釋文則謂「言論自由為人民之基本權利，憲法第十一條有明文保障，國家應給予最大限度之維護，俾其實現自我、溝通意見、追求真理及監督各種政治或社會活動之功能得以發揮」。然而，做為一項憲法所保障的人民基本權利，言論自由亦非絕對的、當然的不受到任何限制。考諸國外立法例，美國最高法院曾發展出所謂「明顯而立即危險」（clear and present danger）、「真實惡意禁止原則」（actual-malice principle）等對於言論自由之審查基準。事實上，在具體情況中言論自由往往與人民其它憲法權利的行使產生競合衝突，在符合憲法第二十三條的條件下，往往言論自由的保障範圍亦必須有所限縮。本文擬就自由權利遑論的法理學為起點，繼而對於我國司法實務進行具體的檢驗，同時兼採比較法與國際法的觀點綜合加以考察。在理論與實務的基礎上，期望為新時代人民言論自由之基本權利理論賦予嶄新的風貌，同時釐清言論自由保障的權利範圍。

The right to freedom of speech is recognized as a human right under Article 19 of the Universal Declaration of Human Rights and recognized in international human rights law in the International Covenant on Civil and Political Rights (ICCPR). Freedom of speech is the freedom to speak freely without censorship or limitation, or both. It also refers often to the synonymous term ”freedom of expression”, which is used to indicate not only freedom of verbal speech but any act of seeking, receiving and imparting information or ideas. In practice, the right to freedom of speech is not absolute under any condition and in any country. The right is in fact commonly subject to limitations. This article mainly focuses on the points and tries to find the answers that what kinds of situations this constitutional right will be rationally limited and how large the category of this right really exists.