Spinoza是西方近代比較早也比較系統地論述思想自由和言論自由的哲學家。他認為，言論自由是每個人不可轉讓也不可剝奪的天賦權利，它對於維護主權者的權威和國家的和平不僅無害，而且必不可少；反之，如果取消了這種自由，主權者的權威和國家的和平都會受到威脅。但是這並不意味著Spinoza主張言論自由不受任何限制，相反，他認為無限制地賦予國民這種自由是極其有害的，言論自由必須有限度。危害社會契約或國家以及蓄意侵犯他人或社會的言論是不能允許的。自由人在言論自由方面應該自律。

Spinoza is one of the philosophers who discussed freedom of thought and freedom of speech systematically in early modern Europe. According to Spinoza, freedom of speech is the natural right of every person, and it cannot be transferred to another. The freedom of speech not only can be granted without harm to Piety and the Peace of the Republic, but also cannot be abolished unless Piety and the Peace of the Republic are also destroyed. But this does not mean Spinoza suggested that the freedom of speech is granted without limit, on the contrary, he maintained that it would be quite fatal to grant it completely. He held that the speech of doing harm to the social contract or the republic or other people deliberately is not permitted. The free man should be self-control in speech.