Within the field of science fiction, a special source of addictive fascination can be found in the sub-genre "Future History", a series of interconnected stories set in a common background that develops over time.
For any story to be enjoyable, we all know how vital interesting characters and settings both are. But in a good Future History there is a unique sense in which the setting also becomes one of the characters. A splendid juggernaut of interlinked themes, alive and growing like a real society, but full of a fictional personality of its own, such a lattice of tales becomes, for the reader, a source of wonder not merely as a new world, but -- as a result of its reliable, organic consistency -- as a new familiarity.
That's the paradox: the more the inhabitants are "housed" in comfort, given a universe with customs, laws and rules which they can take for granted, the more real and therefore more exciting their world seems to us. Against this comfortable backdrop the inhabitants do, of course, have their particular adventures which are exciting for them as well as for us; but we are additionally privileged to watch the lines they are tracing in the greater whole, from the panoramic perspective which is the special virtue of a Future History.
As a matter of fact, for the sake of accuracy, rather than the term "Future History" I would prefer "four-dimensional story-lattice" or "4DL", as the events related in the stories need not be in our future. A series of tales set on ancient Mars a billion years ago, for instance, would fit the sub-genre just as well as a series set on Earth in the next few millennia -- or, for that matter, in the lost continent of Atlantis thousands of years in the past. However, in this article I shall stick with current usage.
My aim is to try to pin down the criteria which make for a successful Future History.
I hope, as I go through my list of points, that the reader will not jump to the conclusion that I am disparaging various great masterpieces of science fiction merely because they do not meet these criteria. Some stupendous works set in the far future, such as Olaf Stapledon's Last and First Men and Gene Wolfe's Book of the New Sun, are largely a different kind of thing, though they have some interesting points in common with the kind of story-lattice which I am discussing.
The criteria I wish to propose are as follows:
1. Volume and Balance.
2. Open-ended complexity.
Volume and Balance:
A successful Future History should, first of all, contain a large number of stories. It should be long. Inevitably, it will not be as long as its fans wish, but I would suggest, for example, that the one big fault in Asimov's Foundation series is that it extends over only 3 volumes, comprising 9 tales. The reader is left yearning for more -- which of course is a huge compliment to the author. (Actually, there is a bit more. A couple of Asimov's early novels are set in that same universe, in periods prior to Foundation, and these help to enlarge the picture; on the other hand I do not regard the much later accretions to the series, different in mood and far less taut in style, as worthy to stand with the original 9.) I have the same complaint to make of Cordwainer Smith, the genius who bridges the storytelling traditions of East and West in a way unique in science fiction, and who was so inconsiderate as to die at the age of 53, leaving us a mere four volumes or so of his Instrumentality saga.
Much more ample in volume are Poul Anderson's dozen or more volumes of the van Rijn / Flandry bipolar series. This is built around two main heroes, living hundreds of years apart but inhabiting the same invented background. Other masters of the genre have given us moderately lengthy oeuvres. Heinlein's Future History consists of five volumes; Larry Niven's of six or more depending on whether you allow the last Ringworld novel and other accretions to count. James H Schmitz's Federation of the Hub series comprises four novels and numerous shorter tales, and amounts to a work of moderately satisfying length. Still, I wish that Schmitz and Cordwainer Smith, in particular, had written another half dozen books at least. They don't make 'em like that any more.
As well as the need for sheer size, a related point is that the size-distribution of the stories should not be too lop-sided. It's nice to have a variety of story-lengths, but there should not be one work which overshadows all the rest in the series. The availability of a crowd of tales is what creates an important part of the desired effect.
Within the wide common background, the stories should have a variety of settings in both space and time. Overlaps in chronology are important, so that although some of the tales should form a consecutive sequence, others should be happening simultaneously in different locations. We want a real lattice, rather than just a string, of events. The Foundation series is a consecutive string, but fortunately the other Future History authors I have mentioned give us simultaneous tales as well.
And there should be a variety of overlaps in dramatis personae, somewhere between the one extreme of each story having its own unique cast of characters, so that no character appear in more than one (this leads to insufficient connectivity) and the other extreme of having the same character appearing in all the stories (this excessively restricts the range of the whole, to what that one central character can do). James Schmitz got it exactly right. In the Hub universe you frequently find the same characters appearing in more than one story, but also you find plenty of "solitaries". I would go so far as to say that if the same main character stars in all the stories, a series can hardly count as a Future History, though it may (like Jack Vance's five Demon Princes books) be a rivetingly good read. Niven, and Cordwainer Smith, like Schmitz, get it right. In his Known Space universe Niven gives us more than one sub-series starring characters who survive through several tales - notably Beowulf Shaeffer who is the hero of five of them. In the Instrumentality saga Smith gives us several separate appearances of the cat-girl C'Mell, the reformer Lord Jestocost and the quester Casher O'Neill. Again, we want to feel we're in a crowd, or, if you prefer, a forest, of options. It's a good sign, therefore, if you can't immediately call to mind how many tales a series has and how many characters appear more than once. It means it has grown satisfyingly ramshackle.
The ideal Future History should also contain cultural complexity. This is not Asimov's forte, nor Heinlein's, though the works of both are multi-political, rich in diverse regimes (especially Heinlein). Niven does better in the cultural area, and apart from human variation he has interesting alien civilizations interacting with ours. Poul Anderson does this too, and his series in particular has an open-ended sprawl of hugeness, looseness and multicultural variety. Schmitz is just about his equal in this respect, though his output is unfortunately not so large. Cordwainer Smith is hard to assess -- he is so matchlessly good at suggesting more than he lets on, it's hard to keep track of the actual content of his stories: it's as though he gives you the key to his unfinished work and lets you dream the rest of it for yourself.
If the work of Jack Vance fitted the bill in other ways, his talent for portraying cultural complexity would make him perhaps the best living writer of Future Histories. However his Gaean Reach novels, though they share a common background, are scattered so widely across that vast setting, that they are unrelated to one another, and there is no sense of chronological sequence or historical development of the Gaean Reach as a whole. (Not that I would want Vance as a writer to be other than he is.)
Rightly handled, detailed time-referencing need never get in the way of a good story, and may enhance it. You're not always thinking of dates when you read a Future History, but a good time-line should be there for when you want to consult it.
The fullest and most detailed timeline of all is given not by an SF author but by J R R Tolkien in an appendix to The Lord of the Rings. Tolkien carefully lists what happened on each day during the six-month climax of the War of the Ring. So far as I am aware, no science fiction author has taken this much trouble. Tolkien in addition provides dates for events going back over 6000 years previous to the events of his main story.
Without needing to go as far as this, a Future History should at least provide the reader with the references to build up an internal chronology of the stories, even if one is not provided in an appendix to the books. Actual dates are preferable. Schmitz gives none, and in any case his Hub series is mostly a lateral cross-section of society during a period lasting only a few years, though with glimpses into more distant past and future. Niven and Anderson have published time-lines -- though I believe that Anderson's was merely approved, not authored, by himself. Asimov provides no time-line but in the Foundation series he is generally quite good at giving dates internally (though at one point there is an inconsistency). Heinlein back in the 1940s allowed his editor, John W Campbell, to print the chart for the author's Future History. Cordwainer Smith had detailed notes for his universe, which he lost by accident, though a basic timeline was drawn up for the collection The Best of Cordwainer Smith.
The all-important common background to the stories of a Future History should itself act out a story, for it cannot be static, any more than the real history of our own world can stand still. On the other hand, though not static, it should be subject, in general, only to the kind of change that befits a civilization's naturally huge inertia -- slow, massive, majestic. Occasional crises, spurts of more rapid change, must occur, and can provide much awe and excitement, but if they occur too often, they undermine the credibility of the entire setting. Captain Future can save the Solar System again and again and it is great fun; but a proper Future History ought to be a bit more dignified.
The masterpiece of massive, inevitable historical change is the Foundation series. The way Asimov manages to combine human excitement and cliff-hanging suspense with a plot that seems to make those qualities unobtainable, and to do it without cheating, is a real wonder to behold. Miraculously, the reader can thrill to the drama of the "Seldon Crises" -- the turning-points in the history of the Foundation -- while trusting all the time (as the citizens of the Foundation themselves trust) that the future is safely worked out. Admittedly, the author enlists an additional source of excitement in the latter half of the series, when an unpredictable mutant throws a spanner into the mechanism of social engineering.
Poul Anderson's Future History concentrates on two eras, both eras of decline: that of the commercial Polesotechnic League and that of the Terran Empire centuries later. In both cases the civilization in decline contain the seeds of change and potential for the rebirth of culture in another form. Anderson's work is full of historical awareness, but in historical variety it is far outclassed by the works of Heinlein and Niven. A very different writer, Cordwainer Smith, outclasses them all by giving an epic sweep to his series which extends over thousands of years.
Lastly, to placate the reader who is wondering "Why the heck hasn't he mentioned Olaf Stapledon?", I will concede that nothing mentioned so far comes close to the multi-billion-year range surveyed in Last and First Men and Star Maker. In LAFM the heroes are entire human cultures; in SM , they are species (and humanity gets a single paragraph). Despite their lack of individual characters, they are absorbing as stories - magnificent science fiction. But they obviously do not fit the category of story-lattice I have been discussing here.
Considered in their own terms, the works I have been discussing are all favourites of mine and I would not have them altered. Considered as Future Histories, and matched against the criteria I have laid down, they all leave something to be desired. This is merely to suggest that the ideal Future History or 4DL is yet to be written. Science Fiction awaits the oeuvre that combines Poul Anderson's sprawl and volume, Isaac Asimov's time-discipline and James Schmitz' open-endedness with Cordwainer Smith's sweep and destiny.