Light is...

"The Left Hand of Darkness", by Ursula K. Le Guin

From the Introdution to the edition I have, by Le Guin as well:
"Science fiction is not predictive; it is descriptive.
Predictions are uttered by prophets (free of charge); by clairvoyants (who usually charge a fee, and are therefore more honored in their day than prophets); and by futurologists (salaried). Prediction is the business of prophets, clairvoyants, and futurologists. It is not the business of novelists. A novelist's business is lying."

From the book itself:
(Orgoreyn is a country, the Orgota its people, the one answering the question is an exile the Domain of Estre inside a neighboring nation, whose prime minister is Tibe.)

"'You hate Orgoreyn, don't you?'
'Very few Orgota know how to cook. Hate Orgoreyn? No, how should I? How does one hate a country, or love one? Tibe talks about it; I lack the trick of it. I know people, I know towns, farms, hills and rivers and rocks, I know how the sun at sunset in autumn falls on the side of a certain plowland in the hills; but what is the sense of giving a boundary to all that, of giving it a name and ceasing to love where the name ceases to apply? What is love of one's country; is it hate of one's uncountry? Then it's not a good thing. Is it simply self-love? That's a good thing, but one mustn't make a virtue of it, or a profession.... Insofar as I love life, I love the hills of the Domain of Estre, but that sort of love does not have a boundary-line of hate. And beyond that, I am ignorant, I hope.'"