This article surveys the classic and contemporary literature on the nature and limits of freedom of expression (or free speech). It begins by surveying the main philosophical justifications for free speech, before moving to consider the two most discussed topics in the free speech literature: hate speech and pornography. The article offers some brief reflections on the large number of arguments which have been offered on these topics. Three newer battlegrounds for free speech are examined at the end: no platforming, fake news and online shaming.

中文翻译：

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言论自由

本文综述了有关言论自由（或言论自由）的性质和限制的经典和当代文献。它首先调查了言论自由的主要哲学理由，然后再考虑言论自由文献中讨论最多的两个主题：仇恨言论和色情。本文对就这些主题提出的大量论点进行了简要反思。最后审查了三个新的言论自由战场：没有平台、假新闻和在线羞辱。