One of the classic ideas of science fiction is the involuntary time traveller struggling to survive in the past. Mark Twain invented it in A Connecticut Yankee in the Court of King Arthur; L. Sprague de Camp gave it its classic genre treatment in Lest Darkness Fall; Poul Anderson's "The Man Who Came Early" offered an ironic comment on the difficulties such a time traveller would face. In Against the Tide of Years, the second volume of a trilogy that began with Island in the Sea of Time, S. M. Stirling shows several thousand Yankees—not from Connecticut, but from Nantucket—doing their best to cope with these difficulties.

Most basically, this is an adventure series, full of dangerous sea voyages and military action. As such, it’s quite successful. The action is both dramatic and easy to follow, and Stirling creates some moments of real tension over the fate of his heroes. Particularly impressive was a short passage that gets the reader into the head of one young Nantucketer going out to meet an invading army drawn by Nantucket's inconceivable wealth—and armed with stolen technology—in just a few pages, making his courage persuasively moving.

The setting for all this, the world of 1250 B.C., is impressively well researched. Like Harry Turtledove, Stirling demonstrates that good historical fiction can readily find a market in the science fiction community. As a linguistics hobbyist, I found Stirling's discussion of linguistic evolution and early writing systems extremely well informed, for example. And there is a constant thread running through all the details: the awareness that the past was different, profoundly different, from our own time; that many of our most basic certainties would have struck our ancestors as wild fantasies, and that their most basic certainties would seem more alien than most of the nonhuman species science fiction writers invent.

One of the best things about Stirling's treatment of the past is that he makes it clear that people in 1250 B.C. were every bit as intelligent as people in 1999 A.D. The single scene that best made this point, in Island in the Sea of Time, had three Nantucketers telling a man from Spain and a woman from Iberia about the Earth being round, only to realize that both of them already knew it and were amazed that the Americans knew it also, as in their cultures it was known only to small elites. But Against the Tide of Years has its share of clever Bronze Age people; I was particularly moved by the Babylonian woman doctor encountering American scientific medicine and grasping its implications.

This series has a third level as well, a philosophical one: an exploration of the relationship between ethics and survival. His main characters, both Nantucketer and ancient, are models of the Greek virtue of phronesis or practical wisdom; and he shows their diverse values as working in various ways to enable them to survive and act effectively. For many readers of Prometheus this will echo Ayn Rand's view of ethics as a functional necessity of human biology, though Stirling makes his points with less philosophical analysis and more action.

Stirling is clearly not a libertarian. For a start, the constitution of Nantucket provides for universal military service, on the Swiss model, an idea few libertarians would accept. But at the same time, he is clearly writing as an American, and an adherent of American values that libertarians prize. His Nantucketers, faced with a dire emergency, promptly hold a town meeting, appoint legal authorities, and begin drafting a constitution and a legal code based on popular sovereignty. They maintain the supremacy of civil government over the military; they turn with relief from central planning, adopted as an emergency measure, to a market economy, with the chief executive reflecting how impossibly complex it is to plan for even a few thousand people; and they carry on the old New England tradition of mechanical inventiveness and ingenuity, setting to work to establish a sustainable industrial civilization and a military that can defend it against looters.

In a sense, this novel is a counterattack against certain ideas popular among today's intellectuals. Stirling shows American civilization and more broadly Western civilization as achievements worth preserving, as not merely just as legitimate as other cultures, but superior to them—or at least, as being entitled to regard themselves so. He shows Nantucket's new contemporary civilizations recognizing its value, each in its own terms: some regarding it as a source of loot and slaves, others as a source of knowledge and trade. And he shows a more personal cross-fertilization also, as Nantucketers and Bronze Age people fall in love and enter into marriages or domestic partnerships, with all the complexities that this leads to.

I don't find quite as much depth in Stirling's characterization as I would like; he tends to sketch his characters' motives and personalities somewhat quickly, especially those of his American villains. The difficulties in intercultural relationships, or the growth of relationships in general, are brought into view from time to time but not worked out in detail. But in a novel of action and adventure Joycean depth of characterization isn't the main point. His characters have enough solidity to keep me caring about their fates for several hundred pages, and waiting to read more when the third volume comes out. Second volumes of trilogies have long been recognized as being somewhat frustrating, and Against the Tide of Years produces some measure of that kind of frustration, with everything half complete and unresolved at the end; but I'm waiting for the third volume just as impatiently as I was waiting for this one a year ago. This is a respectable work, even measured against its eminent predecessors. Stirling moved me, he made me think, and from time to time he made me laugh; there's not much more to be asked of a writer.