The depth of world-building and character development in this book is amazing. The style of world-building is different than what you get in Herbert's Dune universe or Tolkien's Middle-Earth. Maybe it would have been nice to get more of a sense of the whole planet or what happened on Earth in the last few hundred years, but the world-building here is more tightly-focused on the main characters and their immediate environment. And it works. I feel almost as if I lived this book rather than read it. There's only one major human character, Juna, and the reader comes to know her well. Most impressively, though, are that you also get to know several alien characters, each with her or his own distinct personality. The first half or so of the book switches POV chapters between the human and the aliens so that the same event is often described from both POVs. This device could have worn thin, but in Thomson's skilled hands it works well right up until the human character becomes more a part of the alien way of life, at which time she, appropriately and artistically enough, intertwines the POVs more. All this world-building and character development take time, however; the only major criticism I have is that the book starts to drag a little bit in the middle, but it's still well worth the effort.
The Philosophy Report
Philosophically, there's a lot to think about concerning the best way to attain knowledge and to live ethically. Should we abide by abstract rules and sanitized observation (represented here by the Alien Contact rules for engaging with alien life) or should we rely more on lived experience, particular judgments, and direct interaction (represented mainly by the main character, Juna)? This is a big issue in feminist ethics and philosophy of science, and it's fun to see how it plays out in a science fiction setting (although a slightly more nuanced depiction of the other side would have maybe made for an even more interesting book). Along the way, there's plenty of ecology, linguistics, and sociology to consider, not to mention the classic big science fiction theme of encountering the other. On that front, these aliens are plenty different, but still somewhat understandable - they're somewhere between the familiarity of Star Trek aliens and the sheer otherness of Lem's Solaris. All of this makes this book comparable with some of my favorites, especially Octavia Butler and Ursula LeGuin. In the end, this book isn't quite on the same plane as the genius of Butler and LeGuin, but it's definitely in the same direction.