Only the second Delany I've read, and as with the first one, the thought that comes to mind is "what took me so long?" I've loved both - the first for its myth and poetry, and this for the ideas, the prose, the explorations of self and identity. These are hitting exactly in my wheelhouse. This is closer to straightforward science fiction than was The Einstein Intersection, but with a magic all Delany's own.
At its core, Babel-17 is a story of how language shapes identity, possibility, and experience. The words we have, the words we use, and the unspoken assumptions built into those words, and how those assumptions influence what we can and cannot even conceive. That is wrapped around a galaxy at war. (Well, galaxy? Larger? Smaller? Larger than the solar system, anyway - Delany does not feel the need to go into detail, and it really isn't necessary.) Both sides appear to be human. We don't know much about the origins of either - just where we are, right now.
And where we are, sabotages are happening with increasing frequency, accompanied by bursts of what was presumed code that no one has been able to crack. Until they bring in a poet and former starship captain, Rydra Wong, who is the first to perceive that it's a language instead of a code. She amasses a new crew to go after this mystery, and sabotage starts to strike closer and closer to home.
And that's all I'll say about that. The story itself is not the main issue here, but it would still be a pity to spoil it. It is the interplay of ideas and words, like shadows on the water, that continues to strike me, days after I finished it. What Delany does with the core ideas I've written about is truly striking, and provides an emotional as well as an intellectual centre to the story.
But the ideas don't stop there - they come, faster and faster, a universe of assumptions and ideas that Delany doesn't hold our hands through, but poses in provocative fashion. Wong is one of the best female SF characters of the time period that I can think of, interesting and entirely herself - neither superwoman nor helpless. The diversity of the cast puts most modern SF to shame, but it's never the focal point of those characters, just something about them. In a story about how language creates identity, it would be ridiculous to have a whitewashed cast, and Delany weaves them in effortlessly.
Body modification seems to be all the thing, and although some are made uncomfortable by it in the book, many embrace it, and the discussions of what are interesting. And sexuality - the ships seem to run on triads, both corporeal and noncorporeal (yes, as I said, the ideas never stop). In both cases we're presented, the marriages this creates are (or were) one female, two men, but all are married to each other, and again, this causes some discomfort amongst the more mainstream characters, but...I could go on and on about all the lovely detail he's painted in, but perhaps I'll stop.
Have I mentioned that this is less than 150 pages? Yet it never seems hurried, or rushed, or overpacked. This is truly one of those books where every word seems chosen. It's a good book to near the end of the year with, a reassurance of the potentials of science fiction in the past, present, and future.