The short story "Cain" by Russian writer Aleksandr I. Kuprin could be referred to as a genre of moral stories. The main idea here may be related to the Bible's commandment "Thou shall not kill".
The story is about the Captain Markof who was sent by the government to seize a and execute rebels. During the dinner before the execution, "the soldiers cried "Hurrah!" sang songs and danced, but their faces wore a look of stony indifference."
The next day they shot without delay all suspected persons and all those who had no passports. That evening on December 31 after such cruel work the captain Markof had a rest in a room on the half-ruined farm. The sergeant came into the room with a report about the deals that should be done. Finally, he asked what they should do with three locals captured that day. "Shoot them at dawn," interrupted the captain sharply. But sergeant didn't leave the room. He fidgeted from one foot to another, and then said suddenly, with a determined resolution, "the soldiers want to know ... what's to be done with ... the old man?". "Get out!" shouted the captain with sudden anger. The sergeant left the room. The captain remained alone with his thoughts and his sickness. He was ill. He kept the pain inside not showing it to soldiers.
The next morning the three men were brought before Markof and he declared with cynically-eloquent gestures that they would be dealt with as spies. The faces of two of them became pale, but "the old man had only laughed with a certain strange expression of weariness, indifference, and even ... even as it were of gentle condescending compassion towards the captain himself".
The captain returned back to his room. He sat on the bed alone, he was ill, he felt bad. Suddenly he saw a dark figure of the old man in the room. He wasn't a coward but he started up suddenly in mortal terror. He heard the voice, the sound seemed familiar with him. Markof had occasionally heard such voices behind him, voices without color or expression, calling him by his own name.
The author presents in the conversation between Markof and old man, his thoughts about morality, about the history of civilizations. Aleksandr Kuprin put into discussion some difficult questions people face during their lives. The author makes reference to the history of civilizations, he expresses his opinion about restricted time for all social creations.
Eventually, the captain got a report that his order to execute the old man was fulfilled. Markof revealed how ill he was. He said to the sergeant: "That's it, brother ...You must take the command in my place. I ... I ... 'm absolutely tormented by this cursed fever.... And —perhaps—perhaps I may soon be entirely at rest." The author didn't make a conclusion about good and bad, he didn't judge people, he left it for themselves.
This is a link to the text of the story: