All These Worlds Are Yours - The Appeal of Science Fiction

I've been fascinated with science fiction stories for as long as I can remember, although, I must confess, I never thought of science fiction as being mainstream literature. I, like many readers, pursued science fiction as a form of escapism, a way to keep up with speculation on recent scientific discoveries, or just a way to pass the time.
It wasn't until I met with my thesis adviser to celebrate the approval of my paper that I had to think about science fiction in a new light. My adviser works for a large, well-known literary foundation that is considered to be very "canonical" in its tastes. When he asked me if I liked science fiction, and if I would be willing to select about one hundred stories for possible inclusion in an anthology that they were thinking about producing, I was somewhat surprised. When he told me it might lead to a paying gig, I became even more astounded. I went home that afternoon feeling very content: my paper had been approved, and I might get a paying job to select science fiction, of all things.
Then it hit me: I'd actually have to seriously think about some sort of a method to select from the thousands of science fiction short stories that had been written in the past century. When I considered that the ideals of the foundation would have to be reflected in the stories which I selected, something near panic set in: science fiction was not part of the "cannon."
"While I pondered weak and weary, over many a quaint and curious volume of forgotten lore," I reached a decision: I'd first try to figure out what science fiction "was," and then I'd develop a set of themes that related to the essence of science fiction. So, armed with this battle plan, I proceeded to read what several famous authors had to say about science fiction. This seemed simple enough, until I discovered that no two authors thought science fiction meant quite the same thing. Oh, great, thought I: "nevermore." (Sorry, Edgar, I couldn't resist).
Having failed to discover the essence of science fiction, I selected four authors whose work I liked to try to determine what they contributed to the art of science fiction. The authors were: Isaac Asimov, Robert Silverberg, Orson Scott Card, and Arthur C Clarke. At the time, I didn't realize that two of the authors, Asimov and Clarke were considered "hard" science fiction writers, and the other two, Silverberg and Card, were considered "soft" science fiction writers.