The family doctor gave me the Earthsea books when I was a kid because I loved Narnia. I was not ready for them at the time; they really freaked me out. I returned to them later, or at least some of them, with enjoyment, but I still remember that feeling from that early encounter. Decades later I read The Dispossessed, Le Guin's excellent entry in the political science in space subgenre of SF. Last year I finally got around to reading her classic exploration of gender, Left Hand of Darkness. I liked all of these a lot, but Lathe of Heaven is easily my favorite thing I've read by her so far.*
This is her take on a Phillip K Dick style, loss of reality novel, and it is spectacular. It concerns a man named George Orr, living in 2002 (the near future at the time of publication) whose dreams are effective; that is, they actually reshape reality, going as far back into the past as necessary to make the change. He is referred to William Haber, a psychiatrist who comes to believe that Orr's dreams have this power, and then through hypnosis attempts to use Orr to reshape the world. A wave of alternate histories ensue that achieve that effect that happens in most PKD books where the very concept of reality is melted, especially when Le Guin floats the idea that there could be other effective dreamers.
This could have been as far as it went and I would have loved the novel; I'm a sucker for reality bending scifi that doubles as a study of madness/mental illness. Especially when it's packaged in a suspenseful story with excellent prose. But in Haber and Orr, Le Guin is able to explore an interesting set of ethical questions: How much history should they change? What cost is acceptable? What is lost?
"The end justfies the means. But what if there never is an end? All we have is means." In this line Le Guin gets at questions adjacent to those of both the Existentialists and the Pragmatists. It complicates and cuts to the bottom line of ethical decision making. What one chooses to do is what matters. It doesn't negate intent, but it does make it subservient to actions. I will be contemplating this line for weeks.
That such an vital question is embedded in such a well crafted, exciting and heartbreaking story makes this a novel I will return to many times, I suspect.
*It's been a long time for the Earthsea books, so a reread could change this.