“In my fiction I am careful to make everything probable and to tie up all loose ends. Real life is not hampered by such considerations.”

Pop Music's Young Turk, Washington Post, November 18, 2001, https://archive.is/v9Jw, 2012-12-09 http://www.washingtonpost.com/ac2/wp-dyn?pagename=article&node=&contentId=A41014-2001Nov16&notFound=true,

"Document H1000089528" http://galenet.galegroup.com/servlet/BioRC Contemporary Authors Online, Gale. 2010.
Other

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.

"My Hates" (1866).

Preface (1 February 1834)
A Narrative of the Life of David Crockett (1834)
Context: I know, that obscure as I am, my name is making a considerable deal of fuss in the world. I can't tell why it is, nor in what it is to end. Go where I will, everybody seems anxious to get a peep at me … There must therefore be something in me, or about me, that attracts attention, which is even mysterious to myself.

Source: No Exit (1944)