I finished reading Darkness At Noon: A Novel by Arthur Koestler (1941). What an extraordinary book.
It follows the trials and tribulations of an old guard of the Russian Revolution, Nicholas Rubashov. Once a stalward defender and propagator of the Revolution, he turns into a cynic after watching the rise of No. 1 (Joseph Stalin):
What happened to these masses, to this people? For forty years it had been driven through the desert, with threats and promises, with imaginary terrors and imaginary rewards. But where was the Promised Land? Did there really exist any such goal for this wandering mankind?
He reflects of the corresponding "liquidation" of former leaders of the Revolution in the Moscow show trials, suppression of free will of the individual and the tearing of metaphysical mores. All resulting from a grand experiment that Revolution represented. Just before being executed, Rubashov reflects:
It was obviously not enough to direct man's eyes towards a goal and put a knife in his hand; it was unsuitable for him to experiment with a knife...No, one cannot build Paradise with concrete.