“I disapprove of what you say, but I will defend to the death your right to say it.”
This quote has no known author and is recorded as an anonymous proverb.
About this quote
The sentence separates two things that are constantly confused: disliking what someone says and agreeing that they should be allowed to say it. It is widely quoted precisely because it sounds like a paradox, and it is doing careful work rather than making one.
Source: Friendship of the People