
Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 592.
Source: Inside the Third Reich: Memoirs (1970), p. 427
Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 592.
To Albert Speer, autumn of 1944. Quoted in "Inside the Third Reich: Memoirs" - Page 417 - by Albert Speer - History - 1970
To Raoul Nordling
Dallas, Gregor (2006). 1945: The War That Never Ended https://books.google.pl/books?id=PTEV0CPuhRcC&pg=PA173&hl=pl&sa=X&ved=0ahUKEwiUp-aI4dTfAhWKw4sKHYBJDg8Q6AEILDAA#v=onepage&q&f=false p. 178. Yale University Press. ISBN 9780300119886
Quote of Friedrich, 1821; as cited in Authenticity and Fiction in the Russian Literary Journey, 1790-1840 (2000) by Andreas Schönle, p. 108, from memoirs of Vasily Zhukovsky
Variant translation: I have to stay alone in order to fully contemplate and feel nature.
This answer of Friedrich is recorded by Vasily Zhukovsky who asked the painter in 1821 to travel together to Switzerland
1794 - 1840
This illustrates the unsatisfactory character of the First-Cause argument.
"Is There a God?" (1952)
1950s
From the last letter received by his family on September 1974 http://www.memoriayjusticia.cl/english/en_focus-llido.html.
"Inside the New Space Race," Space's Deepest Secrets (S2E17, first aired 5 September 2017, 9:07:01–9:07:19 PM EST).
1977 interview https://www.youtube.com/watch?v=AEWsxCrMM1U in Pitkin County Prison, Colorado