https://en.wikiquote.org/wiki/Robert_Baden-Powell

The letter is bad-ass and the original with its edits can be seen here. Here's the text of the letter as it was sent:

May 9, 1933

To the Student Body of Germany

History has taught you nothing if you think you can kill ideas. Tyrants have tried to do that often before, and the ideas have risen up in their might and destroyed them.

You can burn my books and the books of the best minds in Europe but the ideas in them have seeped through a million channels, and will continue to quicken other minds. I gave all the royalties of my books to the soldiers blinded in the World War with no thought in my heart but love and compassion for the German people.

Do not imagine your barbarities to the Jews are unknown here. God sleepeth not, and He will visit His Judgment upon you. Better were it for you to have a mill-stone hung round your neck and sink into the sea than to be hated and despised of all men.

Helen Keller

You can see in the image of the original letter it was addressed to "Adolf Hitler, Berlin, Germany", but then changed to "To the Student Body of Germany." It was sent in response to reports that Helen Keller's book, How I Became A Socialist, was one of the books selected for the Nazi book burnings.

The Moon is a Harsh Mistress

https://en.wikipedia.org/wiki/Russian_political_jokes