There are times when one has to stand up for principle. I am so proud of my fellow actors who use their public influence to speak out against injustice. At 98 years old, I have learned one lesson from history: It very often repeats itself.
Source, in full
"Kirk Douglas On Trumbo: 'I Was Threatened That Using A Blacklisted Writer Would End My Career'" by Pete Hammond, Deadline (19 November 2015); also quoted in "Kirk Douglas's stunning political courage" by Gene Seymour, CNN (6 February 2020)