If liberty means anything at all it means the right to tell people what they do not want to hear.

George Orwell (1903-1950) English writer [pseud. of Eric Arthur Blair]

Animal Farm, unpublished preface (1945)
    (Source)

The original essay was written in 1945 as an introduction to the first edition of the book, but was left unpublished  It was rediscovered in 1971, and finally published under Orwell's name as "The Freedom of the Press," Times Literary Supplement [of London] (1972-09-15).

More history of this quotation here: If Liberty Means Anything At All It Means the Right To Tell People What They Do Not Want To Hear – Quote Investigator®.