I learned about "Darkness at Noon" from a Herb Simon essay, where he praised emotional story telling as a vehicle for helping people "attend to issues longer, to think harder about them, to receive deeper impressions that last longer". He asked: would you rather read "Darkness at Noon", or verbatim transcripts of Stalin's purges?

The book is historical fiction loosely based on 1930s Soviet Russia. Supposed counter revolutionary movements are being quashed by Stalin. The "hero", Nicholas Rubashov finds himself in the middle of absurd Stalinist show trials, having to publicly admit to crimes he never committed. The intent of his captor is “to gild the right, to blacken the wrong”, ingraining black and white thinking into the masses. The means and ends of the current government are good and just and pure, and everything that opposes it is hellspawn and deserves only one fate. Despite Rubashov's intention to deliver an impassioned speech like Danton did before the guillotine, he finds himself powerless against the Soviet machine, mechanically pleading guilty in the show trial, and then being put to death.

That isn't to say that Rubashov is innocent. As a younger man fervently dedicated to the party, he indirectly condemned his own lover to death, supposedly for the sake of the collective. Now in jail, and softened by sudden onsets of nuance, the former revolutionary has time to reflect. Intensely psychological, the book delves into Rubashov's evolution as he realizes that human life is sacred and no idea is worth sacrificing it for. Rational mathematics does not apply in this domain, and Rubashov eventually becomes a humanist. Fundamentally, Koestler's powerful critique of Stalinism is that the ends do not justify the means.

Late in the book, a distinction between two kinds of suffering:

1. Biological: Inevitable suffering from unmet basic needs.
2. Social: Avoidable suffering from broken social systems.

Koestler observes that Revolution reduces Type 2 suffering but inevitably increases to Tyle 1 suffering. Was the Russian Revolution justified? When is revolution ever justified? Through Rubashov, he wrestles with this issue, acknowledging the need for social change, but questioning the means:

One cannot heal a person mortally ill by pious exhortations. The only solution was the surgeon's knife and his cool calculation. But wherever the knife had been applied, a new sore had appeared in place of the old.

I really liked this book. Not having read the transcript of Stalin's purges, I am going to assume that Herbert Simon was right: Darkness at Noon is well written, interesting, and visceral.