IT is 2100, the eve of human extinction, and where is the last man on earth? Snug in some bosky glade with all the little animals? Hold on, this isn't Bambi. It's Mary Shelley's vision of the end of the world, and The Last Man (1826; reprinted by the University of Nebraska Press, Lincoln, Neb., $5.95 paper) is in Rome, soaking up culture in the ultimate off-season. At the end of time, an indifferent nature offers him no solace; only the remains of civilization, ``the sight of poetry,'' can take ``the sting from thought.'' Shelley's opposition of Nature and Culture is not hard for me to understand. I have stood in the stench of a forest fire and on the streets of ancient Greek cities, half buried in mud and neglect. The aftermath of the forest fire was horrific, but it did not move me like the tangle of columns and inscriptions. In the burned-over area I felt what the Victorians called the sublime: terror safely muted into a dark entertainment. In the lost cities I had to confront my own oblivion. The poet Paul Val'ery said it better: ``...a civilization has the same fragility as a life.''
A few years ago, in his remarkable chronicle, Terminal Visions: The Literature of Last Things (Indiana University Press, Bloomington, Ind., $24.50), W. Warren Wagar recounted the motives for writing endtime fiction. Mary Shelley's intimations of the close of an epoch may owe to the ordeals of her young life, but as Wagar points out, most fictional renderings of the world's demise are symbols, inklings, or invocations of new worlds to come. Whatever disaster the apocalyptic imagination can dish up - the plagues, floods, holocausts, famines, wars, climate changes, resource depletions - there are survivors and new ideas.
It is instructive to read Wagar against Joseph A. Tainter's The Collapse of Complex Societies (Cambridge University Press, New York, $44.50), a recent contribution in a new series that identifies the need to make archaeological information available to a wider audience. (Few fields are more pestered by crank theories that read like tabloid journalism: Find out which galaxy really built Stonehenge.)
Where Wagar, who also writes science fiction, is silky and dramatic, Tainter is almost apologetic for the matter-of-factness of his views. If you have ever read Darwin, you have had a sample of Tainter's prose - and a foretaste of the way the plain-style can pack a wallop.
Tainter examines ancient societies but extends his theory to complex societies in all times and places. His study could be read as Volume 1 of Paul Kennedy's best seller, ``The Rise and Fall of the Great Powers: Economic Change and Military Conflict from 1500 to 2000'' (Random House, New York). Both authors examine specific societies in an attempt to distill general patterns. Both dwell on the fate of political entities, rather than civilizations. This is old-fashioned history, with Tainter overtly eschewing the academic hobby of reading art and culture for symptoms of societal decay.
Tainter concludes that complex societies are likely to collapse when the increased cost of sociopolitical change reaches the point of diminishing marginal returns. In simpler language, that means complex societies do the easiest things first. The mineral deposits mined first are generally the most economically exploited; primary education is the most lasting and the least costly. But when scarce minerals must be retrieved through intensive technologies, and when societies become more dependent on highly specialized training, costs rise in proportion to results. Eventually, the law of diminishing returns sets in, and collapse, which Tainter defines as the sudden loss of an established level of complexity, is imminent.
In his view, collapse is not necessarily a fall into primordial chaos, but a process that returns human society to a more normal, if lower, level of complexity. And what of the floods and famines, climate changes and resource depletions that other archaeologists - and the many writers of endtime fiction - have posited as the cause of collapse? One by one, Tainter looks at these explanations and subsumes them into his general theory. Societies climbing the complexity curve can weather many challenges; societies already overburdened frequently cannot. (After this scorching summer, with its portents of the greenhouse effect, one has to wonder whether this society is at a point on the societal roller coaster where it can act decisively.)
Reading Tainter, I began to speculate on what might happen if the dynamic of societal collapse were to become conventional wisdom. I envisioned presidential candidates rushing to articulate how they would manage the fall. I saw science fiction, which depends on the cause of collapse being conjecturally up for grabs, becoming a ``collectible'' like those potato mashers and eggbeaters one sees spread out on yard sale card tables along the summer roadside.
Then I came to my senses. The apocalyptic imagination would be no more dented by a scientific explanation of societal collapse than it was by Darwin's explanation of ``The Origin of Species.'' Despite Darwin, evolutionary backsliding - people assuming the physical or mental characteristics of a bat, a wolf, and in this summer's hot movie, a capuchin monkey - has remained a viable motif in both popular and serious art. That is because apocalyptic writing always expresses more than it describes; its underlying fears are loosely tied to facts and its hopes wriggle through the rules.
A better question, and one that will be reiterated as we near the millennium, is whether Kennedy and Tainter ought to be read not just as history, but also as apocalyptic fiction, expressing our apprehensiveness as the great powers readjust alignments with the rest of the world.
Mary Warner Marien teaches in the fine arts department at Syracuse University.