"I cannot refrain from expressing my gratitude and that of many of my left wing fellow students to Dewey for his uncompromising honesty in exposing Stalin's show trials of 1935-37. This was not easy at a time when, in the presence of the Great Depression, many intellectuals saw a new hope in the Soviet Union. But to Dewey truth came first; and he (with the great aid of the late Sidney Hook) showed that the trials must be rigged and therefore that the Stalin regime was based on lies. This saved many of us from ever being misled."
January 1, 1970
https://en.wikiquote.org/wiki/John_Dewey