A. E. van Vogt's theory of "unreality" explains in part how he has become so prolific in a literary genre--science fiction/science fantasy--which only recently has experienced a rise in popularity. His theory states that the science fictional sentence must have in it something that requires a contribution from the reader. If the author of reality writing has done a proper job, the reader will not need to make further inferences or contributions. Science fiction requires "unreality" writing, which in turn evokes a contribution from the author, focuses on something the reader associates with or knows about, and presents an enduring reality that will still be alive 20 or 30 years from now when current reality stories are dead. Van Vogt tends more toward science fantasy in that he strives for a "far-out" quality in every story. His science fantasy requires a greater contribution from the reader than science fiction and so may last longer. In addition to his "unreality" formula, van Vogt uses a technique in which he awakens himself every 90 minutes during a night's sleep, which increases his writing output and allows him to expedite solutions to the problems he encounters in his stories. (HTH)