In [b:A Door into Ocean|121606|A Door Into Ocean|Joan Slonczewski|http://d202m5krfqbpi5.cloudfront.net/books/1312029708s/121606.jpg|2640708] Slonczewski used the view points of characters from capitalist Valedon to introduce the communal-living, all female pacifists of Shora. The main plot was tension between Valedon's economic coercion and the Sharers' aim to never cause harm, and it culminated in the question of whether aliens (or rather, people with a completely alien view point that would destroy everything one values) were still too human to be harmed. The next book, [b:Daughter of Elysium|121608|Daughter of Elysium|Joan Slonczewski|http://d202m5krfqbpi5.cloudfront.net/books/1202489024s/121608.jpg|117082], is set thousands of years later, when both the Sharers and Valedon are part of an intergalactic network of treaties and trade. Thousands of years after that comes [b:The Children Star|121607|The Children Star|Joan Slonczewski|http://d202m5krfqbpi5.cloudfront.net/books/1312055902s/121607.jpg|117081], centered around a small colony of orphans trying to create a life for themselves on an alien planet. Prokaryon is inhospitable to outside life but seems to have no sapient creatures...except that the trees are planted in rows, the mountains crafted in pleasing shapes, and brush fires are immediately extinguished with targeted rain storms. The colonists are convinced that Prokaryon harbors some alien intelligence, but unless they can prove it the entire planet will be terraformed for use by the teaming, starving masses back home.
Slonczewski's characters always have well-drawn interior lives. Their conversations range from philosophy to child care arrangements, with each given as much weight as the other. (And I do love that there are some many different family styles presented in these books, from 1 man& 1 woman with biological children to single parents to adoptive parents to people parenting with friends or same sex lovers to the Elysians, whose children are raised in creches by robots.) The ethics and thought experiments she sets up in her books are even more fascinating. In her first book the reader is asked to consider whether aliens are human; in the next, whether machines are. This book makes the question more difficult still: it introduces us to microbes capable of communicating with or even controlling other living beings, and we must again decide whether these creatures, which live on a time scale in miniature to us but have the power to reshape our minds or very flesh, should have the same rights and respect as given other intelligent beings.
Slonczewski writes incredibly thoughtful, fascinating thought experiments, and powers them with likable characters and enough plot to keep the pages turning. I wish more people read these books!