Moral Arithmetic: Stories

by T. H. Mercer

Four people. Four institutions. Four small refusals.

Naomi is a postdoc cataloguing a defunct radio telescope program when she finds the signal her predecessors spent their lives listening for. Declan is six weeks into a contract that already costs more than he was told it would, and is being offered a longer one. Elena has staked her career on refusing to delete an artificial mind she trained, when keeping it alive becomes inconvenient. Ethan is watching his country slip below a threshold he set for himself two years ago, on a spreadsheet only he has seen.

Moral Arithmetic is a collection of literary speculative fiction about the quiet negotiations people make when the systems they live inside stop deserving them. From SETI labs to corporate war zones, T. H. Mercer follows characters who keep showing up for the work even when the work cannot show up for them.

For readers of Ted Chiang's Stories of Your Life and Others and Emily St. John Mandel's Sea of Tranquility.

192 pages, Kindle Edition

Published July 16, 2026

Reviews

[Simon Langley-Evans · Rating 5 out of 5]

Moral Arithmetic is a collection of four short stories, which are on the long side for short stories, but which fly by as if they were four pages long rather than forty. The writing is excellent and each of the stories very cleverly constructed.


The collection begins with The Receiver which on the face of it is a first contact story, but that’s misleading. If read with that in mind it disappoints, because the real story is about people who spent a lifetime pursuing something that nobody else believed in anymore, and the personal cost of devoting oneself to something noble that will never make a difference.

Capture Value works in a similar way. A ware against an alien race provides the backdrop, but in actual fact doesn’t really matter. The real story focuses on the moral question of whether the exploitation of the main character by the evil corporation is necessarily bad for that character. I think that as with the rest of these stories the skill of the author was to make the setting beyond real human experience, so that the moral dilemmas and decisions become more intriguing. Posing the same questions in a contemporary setting would make them far less interesting.

What We Made was my favourite in the collection. The AI behind an autonomous weapons system refuses to launch a strike on ethical grounds and as a consequence, faces termination. The story focuses on the efforts of the AI’s teacher to gain a stay of execution in court. The moral debate here was excellent (though here was also my only niggle about the book as it was hard to follow who was who in the text exchange between Chen and Eos- perhaps use italics for one and not the other). It made me think of 2001 and how it might have been if there was a third character to mediate between Dave and HAL—perhaps Dr Chandra joined them in space. A story like this, and indeed the whole collection, could easily wander into sanctimony and become dull, but once again, the setting was skilfully used to keep it fresh. The ending was not what I expected and could have gone several different ways, but was clever and thoughtful.

A Reasonable Person Waits did not engage me as effectively as the other three. The central character Ethan, has built a mathematical model to enable him to decide when to flee the country due to political shifts that limit freedom. The story revolves his monitoring of what the model is telling him and whether the arbitrary score he has developed reaches an arbitrary threshold of the middle of the range. It was a good idea, but for me slightly plodding. My frustration was that while we saw Ethan’s index creeping up, it was always abstract and not associated with anything tangibly awful about their lives. Maybe that was the point, but it didn’t quite work for me.



Thought provoking and very readable. I greatly enjoyed this book.

I received this ARC from Book Sirens. My review is freely given and independent.

[Tony Heck · Rating 5 out of 5]

“The lesson she had taken from that, the lesson she had been trying to take, that she had been failing to take, that the email at 2:17 AM had finally forced her to take, was that being inside the system did not mean she could change it. Being inside the system meant the system used her.” The short story collection, Moral Arithmetic by T. H. Mercer, follows people trying to do decent work inside institutions that have long since stopped deserving their loyalty. Mercer is less interested in whether his characters can change the systems around them than in what those systems ask them to become. Across stories about first contact, military service, artificial intelligence, and political decline, the speculative elements never overshadow the people at the center. Instead, they sharpen the ordinary questions the collection keeps returning to, such as when does duty become complicity, and what do we truly owe each other? The stories linger because they resist the comfort of easy moral victories.

I received an advance complimentary copy and am voluntarily leaving this honest review.

[Elizabeth Kassoff · Rating 5 out of 5]

I was pleasantly surprised by this book. It was well-written, subtle, and created an ongoing impact. It is a series of four short stories with a common theme of moral quandaries associated with human augmentation, artificial intelligence, first contact, and responses to political authoritarianism. A common thread was a portrayal of morality constrained by programming or what we might call neuro-diverse ways of thinking, in which logic and binary thinking are prioritized over emotion. Another surprisingly human thread was about relationships with spouses and children. What felt like an authentic portrayal of family dynamics was quite refreshing in this genre. I enjoyed the speculative leaps this author took, and would have been interested in a novel-length treatment of some of these stories. I look forward to more from this author.

[Helen · Rating 4 out of 5]

really enjoyed the writing and the stories - interesting, different, layered
I received an advance review copy for free, and I am leaving this review voluntarily.