How to Build a Universe That Doesn’t Fall Apart Two Days Later, by Philip K. Dick:

The strange thing is, in some way, some real way, much of what appears under the title “science fiction” is true. It may not be literally true, I suppose. We have not really been invaded by creatures from another star system, as depicted in Close Encounters of the Third Kind. The producers of that film never intended for us to believe it. Or did they?

And, more important, if they did intend to state this, is it actually true? That is the issue: not, Does the author or producer believe it, but‚ÄîIs it true? Because, quite by accident, in the pursuit of a good yarn, a science fiction author or producer or scriptwriter might stumble onto the truth… and only later on realize it.