Much of the initial controversy stemmed from a 1956 letter Heisenberg sent to the journalist Robert Jungk after reading the German edition of Jungk's book, Brighter than a Thousand Suns (1956). In the letter, Heisenberg said he had come to Copenhagen to discuss with Bohr his moral objections toward scientists working on nuclear weapons but how he had failed to say that clearly before the conversation came to a halt. Jungk published an extract from the letter in the Danish edition of the book in 1956 that made it appear as if Heisenberg was claiming to have sabotaged the German bomb project on moral grounds. Jungk omitted a critical sentence from Heisenberg: "I would not want this remark to be misunderstood as saying that I myself engaged in resistance to Hitler. On the contrary, I have always been ashamed in the face of the men of 20 July (some of whom were friends of mine), who at that time accomplished truly serious resistance at the cost of their lives."