“One of the reasons why I don't get on with most fantasy writing - enchanted sword fantasy writing - is because I think it's emotionally untrue. People behave in very simple ways, unparadoxical ways. What I'm trying to do is bring into fantasy - as I hope I've been able to bring to horror - a certain kind of emotional realism. People have mentioned sex as being a major part of my fiction. An awful lot of horror fiction simply never contained that kind of material. Which seems to me to be extraordinary because most horror fiction is about the body in some way or other, and therefore it should be about sensuality and eroticism every bit as much as it's about corruption.”

Interview with Weird Tales (24 May 2007) http://weirdtales.net/wordpress/2007/05/24/george-rr-martin-on-magic-vs-science/
Context: I think that for science fiction, fantasy, and even horror to some extent, the differences are skin-deep. I know there are elements in the field, particularly in science fiction, who feel that the differences are very profound, but I do not agree with that analysis. I think for me it is a matter of the furnishings. An elf or an alien may in some ways fulfill the same function, as a literary trope. It’s almost a matter of flavor. The ice cream can be chocolate or it can be strawberry, but it’s still ice cream. The real difference, to my mind, is between romantic fiction, which all these genres are a part of, and mimetic fiction, or naturalistic fiction.

"A Conversation With Roger Zelazny" (8 April 1978), talking with Terry Dowling and Keith Curtis in Science Fiction Vol. 1, #2 (June 1978)

It's the art of the possible. Science fiction is the art of the possible. It could happen. It has happened.
A Conversation with Ray Bradbury - Point Loma Nazarene University, Writer's Symposium By The Sea; April, 2001 http://www.cosmolearning.com/videos/a-conversation-with-ray-bradbury-2001-1131/

interview with 3am

Source: Philip Larkin: Letters to Monica

"A Conversation With Roger Zelazny" (8 April 1978), talking with Terry Dowling and Keith Curtis in Science Fiction Vol. 1, #2 (June 1978) http://web.archive.org/web/20070701010155/zelazny.corrupt.net/19780408int.html#2
Context: Yeah, the mythology is kind of a pattern. I'm very taken by mythology. I read it at a very early age and kept on reading it. Before I discovered science fiction I was reading mythology. And from that I got interested in comparative religion and folklore and related subjects. And when I began writing, it was just a fertile area I could use in my stories.
I was saying at the convention in Melbourne that after a time I got typed as a writer of mythological science fiction, and at a convention I'd go to I'd invariably wind up on a panel with the title "Mythology and Science Fiction". I felt a little badly about this, I was getting considered as exclusively that sort of writer. So I intentionally tried to break away from it with things like Doorways in the Sand and those detective stories which came out in the book My Name Is Legion, and other things where I tried to keep the science more central.
But I do find the mythological things are creeping in. I worked out a book which I thought was just straight science fiction -- with everything pretty much explained, and suddenly I got an idea which I thought was kind of neat for working in a mythological angle. I'm really struggling with myself. It would probably be a better book if I include it, but on the other hand I don't always like to keep reverting to it. I think what I'm going to do is vary my output, do some straight science fiction and some straight fantasy that doesn't involve mythology, and composites.

From interview with Anshul Chaturvedi

Interview at Achuka Children's Books http://www.achuka.co.uk/archive/interviews/ppint.php
Context: I have said that His Dark Materials is not fantasy but stark realism, and my reason for this is to emphasise what I think is an important aspect of the story, namely the fact that it is realistic, in psychological terms. I deal with matters that might normally be encountered in works of realism, such as adolescence, sexuality, and so on; and they are the main subject matter of the story — the fantasy (which, of course, is there: no-one but a fool would think I meant there is no fantasy in the books at all) is there to support and embody them, not for its own sake.