Not trying to be a snob, but this is allegedly the story of that quote...
https://en.wikipedia.org/wiki/Evelyn_Beatrice_Hall
In The Friends of Voltaire, Hall wrote the phrase: "I disapprove of what you say, but I will defend to the death your right to say it" (which is often misattributed to Voltaire himself) as an illustration of Voltaire's beliefs. Hall's quotation is often cited to describe the principle of freedom of speech.
And yes, this is one of the credos that I try to live by.  I admit that I can react strongly to what others may say, but I've no desire to silence anyone.