Mother of all introductions!
LeGuin talks about what a sci-fi is supposed to be (she actually relegates that typical non-readers perception to a sub-field: "strictly extrapolative science fiction"), what a fiction writer is, and an artist, what sci-fi tries to tackle, truth, and words, and wow, lol.
I was about to add some bit of quote or other, and realized I have about ten from the intro alone.
Opening of the book then:
I'll make my report as if I told a story, for I was taught as a child on my homeworld that Truth is a matter of the imagination. The soundest fact may fail or prevail in the style of its telling: like that singular organic jewel of our seas, which grows brighter as one woman wears it and, worn by another, dulls and goes to dust. Facts are no more solid, coherent, round, and real than pearls are. But both are sensitive.