"When Hitler attacked the Jews I was not a Jew, therefore, I was not concerned. And when Hitler attacked the Catholics, I was not a Catholic, and therefore, I was not concerned. And when Hitler attacked the unions and the industrialists, I was not a member of the unions and I was not concerned. Then, Hitler attacked me and the Protestant Church - and there was nobody left to be concerned."
German theologian Martin Niemoller (1892-1984). This version of the quote was favoured by the Oxford Dictionary of Quotations.