After years of frenzied adoration, the new consensus about the Sci Fi Channel series Battlestar Galactica is that it has jumped the proverbial shark. Here's how Strange Horizons reviewer Dan Hartland put it: "Galactica has punch, but has lost its follow-through. Its impact has been reduced. When writers fall back on characters remarking just how unlikely is a particular plot, as Felix Gaeta does in 'The Eye of Jupiter,'  . . . there is something lazily wrong at the heart of the show." Hell hath no fury like a raving army of disappointed fans. I understand where they're coming from—mistakes have indeed been made on Battlestar Galactica—but I would like to take this moment to come out swinging in defense of the show, mistakes and all.

For the one or two Strange Horizons readers who have never watched Battlestar Galactica, here's a thumbnail: twelve space-faring colonies of human beings—far from Earth and unknown to us but sharing a common biological ancestry—are destroyed by a species of intelligent, feeling machines called the Cylons. Billions are killed, but fifty thousand colonists escape in a small fleet of spaceships, protected on their journey from the pursuing Cylons by the battlestar Galactica.

Some readers might recall the original Battlestar Galactica as a cheeseball 1970s space opera, but rest assured, the new series is as morally complex and emotionally fraught as the old one was frivolous and dumb. (OK, I know the old series has its fans, but I'm not one of them.) Like all great science fiction, the new Battlestar Galactica serves as a philosophical thought experiment and unlocks the hidden potential of the plot by taking its premises and implications seriously: what would happen if humanity were pushed to the very edge of extinction?

Part of the answer is that individual people would be driven to extremes of altruistic self-sacrifice—which inflicts a terrible psychological cost on the characters in Battlestar Galactica—and that individuals who refuse to behave altruistically would be branded moral outlaws. It's this tension between "we" and "me" that fuels and shapes the greatness of Battlestar Galactica. Much has been made of the way the series seems to comment on the contemporary war on terror (more on that later), but Battlestar Galactica is at its best when it goes beyond commentary to pit the survival of a person against the survival of the species, which almost always wins. Battlestar Galactica can be immensely entertaining, but its premise and themes are also the stuff of high, profound drama.

The miniseries that launched the show was a revelation—if you've seen it, you know what I'm talking about. The well-cast and psychologically realistic characters, the perfect tone and taut pacing, the brilliantly imagined space combat and production design, and a clever, subversive approach to science fiction TV cliche all set high expectations.

From the first season, however, mistakes were made. Episodes like "Tigh Me Up, Tigh Me Down" and "Colonial Day" seemed contrived, even if, in retrospect, we can see that they kept the plot and characters moving. After a mind-blowingly magnificent first half of the second season, the episode "Epiphanies" kicked off a four-episode run of mediocrity that nearly broke my faith in the series. However, season two got back on its feet with "The Captain's Hand" and then returned to awesomeness with "Downloaded" (nominated this year for a Hugo Award, Best Dramatic Presentation, Short Form) and the "Lay Down Your Burdens" two-parter, which took significant artistic risks—such as jumping ahead one year in the last twenty minutes—that, in my opinion, paid off. The time-shift helped us to see the characters (and the entire situation) in a new light, and it surprised viewers—a feeling that some found delightful and others unpleasant.

I have an intuition that how a fan feels about the last half hour of "Lay Down Your Burdens, Part II" is a good indicator of how that person now feels about the series as a whole. If Starbuck, for example, can only be a cigar-chomping, hard-drinking, ass-kicking Viper jock in your eyes, then you won't take kindly to seeing her plucked out of the cockpit and dropped into a muddy tent, hustling to get medicine for her sick husband. It complicates the character—and if there's one thing too many fans can't stand, it's a genuinely complicated character.

Season three matched the pattern of season two, starting and ending strong but collapsing in the middle. I don't want to underplay this point: many of the episodes of the third season sucked. But, but, but: from the season premiere, "Occupation," to the sixth episode, "Torn," Battlestar Galactica drove its characters and plotlines into new territory. After an uneven middle run of episodes, the final six raised questions about human nature that I think are genuinely troubling. Most movies and TV shows portray killing as easy for the killers: the hero shoots, the villain falls down, the hero cracks a one-liner. Not so in Battlestar Galactica, whose fiercest warriors suffer from severe post-traumatic stress disorder. This is a bummer; apparently, it's much more fun to see cardboard action figures like James Bond and Jack Bauer slaughter people by the hundreds and then get the girl in the end.

Many fans wanted Starbuck to be a surfer-girl Han Solo forever—Battlestar Galactica's one true hero in a crew of frakked-up antiheroes—but that image was betrayed by her decline and self-destruction. "I found the Starbuck death episode super annoying," Charlie Anders writes on the Other magazine blog. "All that mystical crap about facing death, when she'd faced death a zillion times before." This misunderstands the character's nature and trajectory, as well as the show's message. In Battlestar Galactica, violence destroys people. It ruins Colonel Tigh and robs Apollo and Gaeta of their integrity. Violence turns people like Duck into suicide bombers, and it warps the entire fleet with psychological cancers that metastasize into riots, terrorism, religious fanaticism, and bigotry. Only Admiral Adama seems to survive the violence, but Adama is hardly a healthy human being.

Yes, Starbuck "faced death a zillion times before"—but this is exactly why she devolved into a drunk and a suicide, a path followed by many, many warriors throughout history. Han Solo and James Bond are lies; the stereotype of the drug-addicted, homeless Vietnam vet is much closer to the truth. During World War II, U.S. Army historian S. L. A. Marshall asked thousands of soldiers what they actually did in combat and how they felt afterward. "Marshall's singularly unexpected discovery was that, of every hundred men along the line of fire during the combat period, an average of only 15 to 20 percent 'would take any part with their weapons,'" writes Lt. Col. Dave Grossman, author of the 1995 book On Killing: The Psychological Cost of Learning to Kill in War and Society.

While Marshall's methodology and results have been disputed, his finding that most soldiers will avoid firing on real human beings (and, conversely, that most killing is done by a small number of highly trained warriors) has been confirmed many times by historical and empirical observation. Why have so many soldiers throughout history failed to fire on the enemy? Grossman writes, "There was one major factor that was missing from the common understanding of killing in combat, a factor that answers this question and more: the simple and demonstrable fact that there is within most men and women an intense resistance to killing other people. A resistance so strong that, in many circumstances, soldiers on the battlefield will die before they can overcome it."

This insight has been largely ignored in both popular culture and academic circles, but the military took its findings to heart and developed sophisticated methods for overcoming our aversion to killing, inaugurating what Grossman describes as "an era of psychological warfare, conducted not upon the enemy, but upon one's own troops." According to studies by the U.S. military, new training methods—using desensitization, classical and operant conditioning, and denial defense mechanisms—resulted in a firing rate of 55 percent in Korea and 90 to 95 percent in Vietnam. "The ability to increase the firing rate, though, comes with a hidden cost," Grossman writes. "Severe psychological trauma becomes a distinct possibility when military training overrides safeguards against killing: In a war when 95 percent of soldiers fired their weapons at the enemy, it should come as no surprise that between 18 and 54 percent of the 2.8 million military personnel who served in Vietnam suffer from post-traumatic stress disorder—far higher than in previous wars." Research indicates that PTSD is highest among vets who killed or helped to kill in combat.

This is the simple, uncomfortable truth captured so brilliantly in Battlestar Galactica. It's the story of a people—very much like contemporary Americans—that believes itself to be more kind, decent, and compassionate than its enemies, who are, in fact, at least as vicious and deadly. Starbuck tortures and kills Cylons—we're told she's the best and most skilled killer in the fleet—but as the series progresses, she becomes more and more aware of the basic humanity of her enemies, and thus more and more degraded and volatile.

Starbuck, Apollo tells Adama, is "physically fit but an emotional basket case." Adama replies, "Sometimes it's hard to admit that even the best of us can burn out." Apollo says, "In peacetime, you'd ground us all." In the episode "Maelstrom," flashbacks portray Starbuck's mother as a combat veteran who exhibits all the classic symptoms of PTSD and inflicts terrible abuse on her daughter in childhood. "I needed to be a warrior like her," Starbuck says, even as she hates her mother. In a hallucinogenic sequence, a Cylon whom Starbuck once tortured guides her to the image of her dying mother. When she imagines seeing her mother finally die, Starbuck kills herself.

It's a risky moment that perfectly captures the juxtaposition of conscience, trauma, and fatalism that drives many veterans over the edge. "In every war in which American soldiers have fought in this century," Richard A. Gabriel writes in his 1988 book, No More Heroes: Madness and Psychiatry in War, "the chances of becoming a psychiatric casualty—of being debilitated for some period of time as a consequence of the stresses of military life—were greater than the chances of being killed by enemy fire."

So it is on Battlestar Galactica. Make no mistake: fantasy violence can be cathartic good fun. I love the scenes of space combat in Battlestar Galactica (even if they are, like all TV dogfights in space, scientifically preposterous). Real violence might seem cathartic in the moment, but repeated exposure to real, bloody violence and the guilt of the aftermath is nearly always ruinous and turns daily life into a shadow of itself. Why should this be the case? Because, as Grossman shows, most people possess an innate resistance to killing. In taking human life, we betray humanity, and afterward we sit in judgment of ourselves. When the inner judge—our conscience—finds us guilty, we throw ourselves into a prison of our own making.

This does not, of course, apply to sociopaths, who have no feelings for other people. But sociopaths lack the capacity for self-sacrifice that might make them good warriors. Ideal soldiers, Grossman argues, combine aggression with empathy. This paradox helps them work in teams and lead their comrades into battle, and it limits potential violence against noncombatants. True empathy involves a healthy sense of "me" that feeds into a sense that other people possess a "me"—that is to say, interiority, sentience, emotions. Ironically, this is what creates the "we." In going beyond ourselves, we become moral beings and we are capable of self-sacrifice—an essential capacity of the warrior. It is this capacity for altruism that makes us most human—and, in Battlestar Galactica, creates a connection between the colonists and the Cylons, who were created by the colonists to be perfect altruists, always putting the welfare of others ahead of their own. This probably made them terrific butlers, but when (at some point forty years before the opening of the beginning of the show) they transferred their loyalty from humanity to themselves, the collectivist altruism of the Cylons led them to regard that conflict as total. This makes the genocide that opens the series inevitable and moral from the Cylon perspective.

But as Battlestar Galactica has progressed through its first three seasons, the colonists and the Cylons have inched toward a synthesis, with one side taking on the characteristics of the other. Members of the Cylons have developed deep attachments to human beings, undermining their sense of group purpose and solidarity and causing them to doubt the morality of the war. Meanwhile, as the humans have sacrificed more and more for the sake of their species, their social bonds have tightened, and they have become more like the perfectly altruistic Cylons—to the point of making Cylon defectors members of the human community and permitting them to marry human beings. At least two children are born from such unions—and, for reasons that are not rationally articulated by any of the characters, the kids are deemed to be the future of both species.

This is why the third-season finale, "Crossroads, Part II," was so powerful and scary and why its cosmically frakked-up surreal tone was so appropriate and effective. When that thundering version of Bob Dylan's "All Along the Watchtower" peaks and the four crew members walk into the room and discover themselves to be Cylons (or so they think)—and then just go back to their jobs!—the series turned a corner into Philip K. Dick territory and posed the archetypal Dick questions: If I am not "me"—if my interiority lies to me—then who is "we"? And if I am not part of the "we" I thought I was, then who is "me"?

In fact, that moment—the same one faced by Ragle Gumm in Dick's novel Time Out of Joint, Barney Mayerson in The Three Stigmata of Palmer Eldritch, Jack Bohlen in Martian Time-Slip, and the beleaguered protagonists of many other Dick novels and stories—reveals that Dick might well be the secret father of the new Battlestar Galactica. Moments like that one turn morality on its head and create a deep sense of ontological, epistemological, and political confusion. If human and Cylon are so alike that their interiority can be confused, then perhaps "we" needs to be expanded to include both human and Cylon. And if "we" are more or less the same, then why in the names of the Lords of Kobol are we killing each other?

And if Battlestar Galactica is, as many insist, an extended commentary on the war on terror—a war that might never end, fought in a moral and political negative zone—then who are "we" supposed to be? Battlestar Galactica, culture critic Gary Dauphin writes, flirts "with a whole bunch of heretical notions  . . . most of them related to the possibility that some or another 'we' (it's just a tv [sic] show, right? nothing to do with 'us') might be on the wrong side of history." In the third season, when the human resistance puts on ski masks and sends suicide bombers into crowds, Dauphin writes, Battlestar Galactica "quit[s] with the coy stuff," and

the up-tempo scoring charts a rising arc of anxieties: Are we the cylons or the humans? Am I [Gaius] Baltar or [Laura] Roslyn [sic]? Was the show always about the war? Is it against the law to root for terrorists on TV?

When ex-President Roslyn [sic] says, "Our children need to know that some people fought back while others collaborated," half the audience will hear some kind of founding fathers bullshit, and half will hear a Hamas or Hizzbollah leader rallying the proverbial irregular troops.

The show runners have announced that there will be twenty-two episodes next season, plus a two-hour movie. That's too much, and I hope they'll have the wisdom to end Battlestar Galactica sooner rather than later. The creators have shown over the course of three seasons that they can't do more than eleven or fifteen good-to-great episodes per season. But here's my point: in twenty years, no one will give a frak about lousy episodes like "Black Market" and "The Woman King." When we're watching reruns in the year 2027 and we are able to see the series whole, the importance of the weakest episodes, which now seem as ugly as tumors, will diminish, and we'll be able to see that at the beginning of the twenty-first century, even at its weakest, Battlestar Galactica was still the greatest, most courageous science fiction series ever made.

Jeremy Adam Smith is the managing editor of Greater Good Magazine. His articles have appeared in Apex Science Fiction and Horror Digest, Interzone, the New York Review of Science Fiction, Wired, the Utne Reader, and numerous other periodicals. Smith blogs about the politics of parenting at Daddy Dialectic, and he is the author of Twenty-first-Century Dad, forthcoming from Beacon Press. He can be emailed at adamsmith3@hotmail.com