自由是体现人的本质和意愿又不损害他人与社会利益的自己由着自己,是人类永恒而普遍的追求。约翰·斯图尔特·密尔在其《论自由》中将自由限定在社会领域,积极地从理论上对其自由原则加以详细论证,尤其是为言论自由提供了富有说服力的论证。密尔高度强调言论自由对社会发展的推动作用,主张言论自由的绝对性,认为言论自由是其自由原则的基本。笔者尝试对密尔思想言论自由予以理解剖析,探寻其合理性和局限性。 Freedom is the eternal and universal pursuit of mankind, which embodies itself in essence and intentions without harming the interests of others and society by himself. In his “On Freedom”, John Stuart Mill defined freedom in the social field and proactively theoretically demonstrated his principle of freedom in detail. In particular, he provided a persuasive argument for freedom of speech. Mill highly emphasizes the role of freedom of speech in promoting social development, advocates the absoluteness of freedom of speech, and holds that freedom of speech is the basic principle of freedom. The author attempts to understand and analyze Mill’s freedom of speech and to explore its rationality and limitations.