This is a good book, and I think I must read it again soon to appreciate it better but my initial impressions are that, while it stretches the intellect with many new possibilities of Matrix-like proportions (subjects include: almost infinitely regressive computer simulation; the ability to lead multiple digitally cloned lives; speculations on personality, memory and the relativity of time in an environment where one can create and run copies of oneself; worlds that are completely malleable, with the ability to replicate and provide themselves with unlimited virtual space and processing power, and a scenario in which a simulacrum of biological life allows the evolution of beings whose sentience, increasing intelligence and consciousness are capable of shaping the bounds of their 'reality' simply through the operation of the organising principles of mind itself), it leaves the soul somewhat detached.There are real people in here, with their own existential crises but their speculations are philosophical, not emotional; their problems appear to the reader to be just, well, permutations, variations on a theme, a libretto, an equation. Perhaps that is the intention of the author, to show through the lack of depth developing in these digital adventurers as they delve deeper into their new simulated realm, the fundamental difficulty of remaining fully human. However, I doubt it. At one point, a lead character craves to be amongst flesh-and-blood people again but despite the apparently plaintive cry, one has no authentic connection to the personal reasons why this might be, any more than you could say that an addict craves their drug for affective rather than reasons of altered cellular chemistry.Recommended as a tightly-written piece of speculative fiction only. The author probably had nothing else in mind, and certainly don't expect to be engaged on multiple levels. ( )

I read this when it was released in 1995 and still have my copy. It unerringly makes my list of top 10 speculative fiction works.

At this far of a remove, I don't remember the details beyond modeling a slightly simpler universe inside of a computer, but It opened up a new world of science fiction for me. This was one of the first science fiction books that I read the year it was published, and thus the first without the "past looking forward through a present not my own" feeling that Asimov and Heinlein and many others gave me. ( )

[Amy] Like quite a few of the books I've picked up in recent months, I was intrigued by Jo Walton's review of this one in her re-read-books feature on Tor.com, though I don't actually remember now what precisely made me move it to my to-read pile. It was certainly a fascinating novel of ideas, though, even if the ideas themselves are not so revolutionary as they were in the mid-90s ... at least not to me, anyway, though a debate in which my husband is currently embroiled on a discussion forum for Second Life at the moment indicates to me that perhaps not everyone is as comfortable as I am with the reality of the virtual. And while that specifically is not one of the central ideas of the novel, I do think it's a prerequisite.

In short, while I find rather a lot of the things the protagonists came up with to surmount the central issues of computation power and so on astonishingly handwavy, I found the book itself quite interesting, and a useful look at some ideas that I think are, some 15 years after this writing, quite possibly on the verge of becoming relevant.
[http://weblog.siliconcerebrate.com/ze...]

Very interesting concepts, but a bit overdone. It was very hard for me to get through the last 50-100 pages. ( )

Egan takes the Paul Durham character and scenario that he created in his story 'Dust' and takes it further, adding other characters and personalities to his exploration of looking at the simulation of people and running them, or living in, a virtual environment.

He explores what class differences will mean in such a world, while Durham works and schemes to continue his experiments with the help of others.

http://notfreesf.blogspot.com/2007/04/permutation-city-greg-egan.html ( )