I’ve read a few books on the topic of neuroscience and how the brain functions. I’ve also read a few science fiction books about artificial intelligence, robotics, and simulating human behavior. A few of these books have went as far as portraying the concept of uploading the contents of the brain to a computer. It begs the question, what is human conscience, and can it be portrayed in software? It’s an ambitious and complex topic, and one that Greg Egan tackles in Permutation City.

The story is set in the near future. Humans are able to upload their conscience to a computer. It is an expensive process, and because of its price, it is generally reserved for the wealthy. It’s also expensive to maintain due to the computing power required to simulate the person within their environment. Its so intensive that the amount of time that passes in the simulated environment can be anywhere from 10x or more slower than real-time. For example, 1 hour in the simulated environment can equate to 10 or more hours in real-time.

Another interesting facet of the story is that those still alive who choose to upload themselves can talk to their “copy.” It makes for some interesting dynamics as Egan portrays the process from both sides of the fence – from the actual person’s perspective as well as the copy’s perspective. Think about it, if you know you were really just a copy of your real self, would you want to continue living that way, or would you pull the plug on yourself if that capability existed?

Besides exploring the ramifications and ethical considerations of copying one’s self into the digital realm, Egan explores the concept of creating a virtual world that is self-replicating and could run itself. He not only introduces the concept but also explores it in detail. I was impressed by the amount of detail Egan gets into when describing the creation of the environment and how it works. It’s clear that he’s thought about it, a lot. It even leads you to the point of questioning whether our existence is real, or if we are just a simulation running inside of another environment, that could be inside another environment, and so on.

Permutation City is an interesting and deep exploration into the concept of simulating the human conscious along with the moral and ethical ramifications of doing so. While interesting, the book is detailed and complex. Even for someone like myself, who I would consider moderately savvy when it comes to technology, I had a difficult time following the details and the story arc. I’ll admit that I was in well over my head.

For that reason, I wouldn’t recommend the book to just anyone. You need to have a deep interest in simulating the human condition in software and have a strong technical background to follow the book. Otherwise, I might suggest reading one of Blake Crouch’s books, such as Dark Matter or Recursion, or William Hertling’s Singularity Series. These books will provide with a good introduction into the technical and ethical challenges around simulating the human condition without getting as deep into the weeds discussing the technology behind it.