I speak, of course, not about our own future, which is the major subject matter of most science fiction, but about the future of the people in the future, the future that they would presumably be looking forward to with curiosity and concern.

After all, what has always characterized the human species is our ability to look beyond the present to envision and contemplate our past, and our future, as distinct realms of existence. And the last century in particular has witnessed an explosive growth of interest in the human future, as evidenced not only by the vast popularity of science fiction, but also by the increasing numbers of people who earn a living by promising to provide others with knowledge of the future—either through mystical revelation (the prophets and psychics) or scientific calculation and deduction (the "futurists"). This fascination with tomorrow shows no signs of abating, and thus will presumably continue, and perhaps even intensify, in the future.

However, there is little evidence of such an ongoing interest in the futures depicted in science fiction. For one thing, the genre of science fiction itself is rarely observed in these futures. I have spent some time trying to recall some examples of stories about the future that feature science fiction writers, and have so far come up with four: Arthur C. Clarke's The Sands of Mars (1952), in which the protagonist, science fiction writer Martin Gibson, embarks upon an actual flight to Mars, enduring in the process some good-natured ribbing about his inaccurate predictions regarding space travel; Robert A. Heinlein's The Rolling Stones (1952), wherein the spacefaring father and grandmother of the youthful heroes spend some of their time writing episodes of an absurd space opera featuring the machinations of the Galactic Overlord; Farmer's story "Riders of the Purple Wage" (1967), offering a brief appearance by science fiction writer Huga Wells-Erb Heinsturbury; Ben Bova's The Starcrossed (1975), the disguised story, set in the future, of how television producers ruined Harlan Ellison's science fiction series The Starlost; and Philip José. There are doubtless other examples to be cited, but they cannot be very common, and it is interesting that the science fiction writers we do find in the future are usually there to be satirized as inept prognosticators. But it is not simply the absence of science fiction writers which seems odd: where are the prophets, the psychics, and the futurists in the futures of science fiction? Again, there are exceptions to discuss, but one can perhaps, at this point, concede the general point that, for the most part, the people in the futures of science fiction display relatively little interest in their own future.

Why might this be the case? There is one obvious answer to be drawn from the standard argument advanced by Stanislaw Lem and others, that science fiction writers, as human beings, are inherently incapable of imagining truly alien beings, meaning that all aliens in science fiction are nothing but disguised humans. In parallel fashion, one might claim science fiction writers are inherently incapable of imagining genuine futuristic humans, meaning that all future humans in science fiction are nothing but disguised present-day humans. And, as disguised present-day humans, they are already inhabiting their own future, and hence have no interest in more distant futures. Still, I've never been particularly fond of Lem's argument, believing that writers actually can imagine, and sometimes have imagined, truly alien beings, and there are stories which have achieved at least partial success in imagining future human beings who are actually different from us in their attributes and attitudes. And such truly different humans should be displaying, among other things, an interest in their own future.

Another argument would be that people who sit around reading science fiction novels, or anxiously asking psychics or futurists for information about coming events, are not dramatically interesting characters; the protagonists of science fiction are typically men and women of action, much too intent upon creating their own futures to display any concern for what others might be predicting about those futures. Yet even the most energetic science fiction heroes never engage in nonstop activity; during their adventures, they also eat dinner, socialize at bars, flirt, and indulge in long philosophical discussions. It would not seem unusual to occasionally observe them consulting a fortune-teller or talking about an outlandish new science fiction story; yet they never seem to do such things.

And there is a broader objection to the entire notion that science fiction heroes are proactively building the future as an alternative to speculating about it; for if we ponder the grandest and most expansive epics of science fiction, the ones that seem most focused on revelations of humanity's ultimate destiny, we discover that their characteristic direction is in fact backwards.

Consider the one science fiction saga that offers the strongest counterexample to my general observation, Isaac Asimov's Foundation series. This is a story centering upon one citizen of the future, Hari Seldon, who is keenly interested in his own future and has actually devised a solid scientific method for predicting humanity's future in the coming millennia—the discipline of "psychohistory." Concerned because his equations indicate that the Galactic Empire will soon collapse, leading to thousands of years of damaging chaos before order is restored, he sets up two secret organizations whose actions, guided by the predictions he prerecorded before his death, will help to shorten the unsettling transitional period. The inevitable conclusion to this long drama would be the triumphant reestablishment of a new, improved Galactic Empire, with assurances of many years of further human progress to come under its benevolent rule.

Yet Asimov never gets there. After Seldon fails to predict the disruptive impact of a single mutant, the Mule, his later prophecies no longer seem quite as important to the people of his future, and when Asimov returned to the series after three decades, he was most intent not upon advancing the story further, but rather upon integrating his robots into the saga as unseen manipulators of humanity and introducing the hive-mind of Gaea as a new, alternative human future. After his characters finally discover the legendary planet Earth in Foundation and Earth (1986), Asimov abruptly lurches his story back in time to the lifetime of Hari Seldon, whose efforts to establish his foundations are detailed in two additional novels, Prelude to Foundation (1988) and Forward the Foundation (1993).

Another grand science fiction epic, Robert A. Heinlein's loosely-structured "Future History," was belatedly extended in Time Enough for Love (1973) to a time when the apparently immortal Lazarus Long has grown tired of living in a largely utopian future. Yet once his interest in life is reignited, he resolves to return to the time of World War I to meet and romance his mother, and he almost dies on a European battlefield before being rescued by family members. The story then inches forward in The Number of the Beast (1980) to grant future humans access to innumerable parallel universes, while also discovering that they must now engage in a vast, difficult struggle against the mysterious, inimical beings called the "Black Hats." But this enormous cosmic war never concludes with the anticipated victory of humanity; instead, after another novel that does nothing to advance the saga, The Cat Who Walks Through Walls (1985), Heinlein again sends his story back into the past to tell the story of Lazarus Long's mother in To Sail Beyond the Sunset (1987).

(I will concede that the author of another renowned science fiction saga, Frank Herbert, resolutely kept his Dune saga moving forward, with characters consistently focused on their future as they strived to fulfill ancient prophecies; but his successors Brian Herbert and Kevin J. Anderson, after doing what they could to further continue the story based on Frank Herbert's notes, eventually succumbed to the pattern by returning to the story's past to write several prequels.)

Finally, one might ponder the grandest epic of science fiction television and film, the various incarnations of Star Trek. (Star Wars is not relevant here because, after all, that story began in the distant past.) When he was first reviving his classic series, Gene Roddenberry chose to move one hundred years in the future for Star Trek: The Next Generation (1987-1994) so as to allow for the introduction of new technologies and new alien civilizations. When a third series was contemplated, one might have expected another leap into the future for similar reasons; but instead, the next two series, Star Trek: Deep Space Nine (1993-1999) and Star Trek: Voyager (1995-2001), both took place at roughly the same time as the second series. To carry on the story in a fifth series, producers strangely chose to lurch back in time to tell the story of the Enterprise before the first series began in Star Trek: Enterprise (2001-2005). And, after the failure of that series and an additional film featuring the cast of Star Trek: The Next Generation, the latest effort to extend the franchise, the forthcoming film Star Trek (2009), is also taking a backward step to depict the crew of the first series in their younger days.

Why did none of these sagas continue moving in their original, and logical, direction, namely farther into the future? What, exactly, were their creators afraid of?

In the cases of the Foundation series, Heinlein's Future History, and Star Trek, I would argue we can discern disturbing future possibilities that led their authors to shift their attention to the more comforting arena of their stories' pasts. Isaac Asimov did not really want to deal with the obvious issue raised by bringing his robots into the story: since robots are now clearly superior to human beings in every way, why should they forever be content to keep themselves out of the picture in order to benefit humanity? Won't they eventually be smart enough to devise a Minus-One Law that would logically allow them to pursue their own destiny without feeling obliged to perpetually slave away as humanity's nannies? And Asimov is also obviously ambivalent about this business of a group intelligence—unwilling to reject it as improper or inhuman, but also far from thrilled by the prospect. But if allowed to survive, won't the pattern of group intelligence represented by Gaea inevitably prevail? Rather than wrestle with such vexing questions, Asimov was surely more attracted by the opportunity to avoid them by writing prequels, rather than sequels, to the Foundation series.

Heinlein had similar reasons for not wishing to advance his Future History; if people become effectively immortal and gain the power to travel to innumerable alternate universes, there will obviously come a time when Lazarus Long's (and Heinlein's) cracker-barrel philosophy will be utterly irrelevant to the concerns of a transformed humanity. And his Future History also includes the unresolved issues of advanced artificial intelligence (Lazarus's robot companion Minerva, who chooses to become human) and group intelligence (introduced, and vehemently rejected by Lazarus Long, in Methuselah's Children [1941]). Further stories about people growing up in Heinlein's early-twentieth-century Missouri were visibly more appealing to the aging Heinlein.

As for Star Trek, one must first recognize that no imaginable law of physics would ever limit teleportation to the distance of a few hundred miles; that must be a purely technical problem that could eventually be resolved, leading to the obsolescence of starships and a different sort of Federation of Planets linked instead by Stargates. The implications of the Holodeck are also disquieting: if people now have the power to create and inhabit elaborate and satisfying virtual worlds, why, exactly, would they really be interested in traveling to and colonizing other worlds? Wouldn't it be easier, and even better, to simply program one's Holodeck to simulate an attractive new planet? And there is the broader contradiction, observed in Star Trek and elsewhere, of a future world where everything is scientifically advanced, yet humanity has implausibly retained the lifespan, abilities, and attitudes of the twentieth century. As a science fiction story keeps moving into the future, isn't it virtually inevitable that, at some point, there will occur some fundamental change in the human condition?

At this point we arrive at the real reason why the people in our science fiction futures are so disinclined to ponder their own futures.

Here is the paradox: on the one hand, we fully recognize, as a matter of scientific and historical logic, that the people of the future are going to be vastly different from us, due to natural evolution, artificial enhancements, and/or changed circumstances—just as we are vastly different from the primates who were our distant ancestors. On the other hand, we really don't want to hear any stories about our transformed descendants, and we may even be fundamentally incapable of creating or appreciating visions of such transformed descendants. Even Arthur C. Clarke, who has been more willing than most authors to take his readers in that direction, has only offered brief glimpses of how radically strange the people of the future might be—the children merged into a hive mind at the conclusion of Childhood's End (1953), the final image of the Star Child in 2001: A Space Odyssey (1968). The vast majority of authors do not want to come anywhere close to the point when future humans might begin to seem unrecognizable to present-day humans. So, they create stories about the future featuring people who are more or less just like us, and these people rarely if ever consider or speculate about their own future, since that would necessarily involve pondering fundamental, drastic changes in their very nature. Furthermore, if any of these stories continue on too long and approach a moment when their people might start to look different, the authors bring their stories to a halt and return to the familiar territory of previous episodes.

I am not the only commentator who has noted science fiction's reluctance to explore the prospect of a radically altered humanity: scholar George Slusser has described the moment when humans become posthumans as "the Frankenstein barrier" and discusses how various authors have contrived to approach, but avoid crossing, this barrier. My innovative suggestion is that this awareness, and this uneasiness, regarding the future transformation of humanity is not limited to a few authors but in fact permeates the genre—as evidenced not by overt references to our transformed successors but by an easy-to-overlook absence of evidence: namely, future characters' lack of interest in their own future as a device to avoid ever considering such possibilities, as well as consistent authorial efforts to prevent their lengthier sagas from extending too far into the unknowable.

Still, while writers may be reluctant to explore a future human species which is fundamentally different from our own, I do not believe they are incapable of doing so. They may simply need to keep following Theodore Sturgeon's famous advice to science fiction writers—"Ask the next question." In creating and writing about their future worlds, authors should always be thinking, "Where is this world going? What is this future going to look like in fifty years, in five hundred years, or in five thousand years?" Their future characters should be keenly interested in such questions, just as we are today, and they should regularly engage in debate and discussion about their own possible futures. Not only would their characters seem more realistic, but their comments and speculations might function to move familiar stories into unfamiliar territory and engender genuinely new ideas about humanity's future—something science fiction has always been supposed to provide, yet so rarely delivers. And if their stories happen to extend into several volumes, writers should follow Herbert's example and let their successors write the prequels while they resolve to keep pushing their sagas further and further into the future—which is, after all, where science fiction belongs.