I confess I find the prospect of bringing back lost species fascinating. Did anything make the movie Jurassic Park worth watching except the idea of bringing back dinosaurs? Likewise, the idea of meeting a live Neanderthal is fascinating. And think what we could learn: Could they speak? Could they learn a language? And what’s really so great about Geico car insurance?

At the same time, the prospect of bringing back an extinct human species is forehead-puckering. At the very least, as futuristic as the idea sounds, it’s worth turning the idea a little in the light. And the gauntlet has been thrown down: a genetic scientist I know has said to me, in effect, “All right, you thinkers, what do you have to say about this?”

Unfortunately for me, I am hard pressed to know what to say.

Church apparently told the Times that the way to do the work without running into any ethical problems would be to insert the Neanderthal genome into a chimpanzee cell. The chimp cell would be reprogrammed to an embryonic state, inserted into a chimpanzee’s womb, and brought to term. In a way, the product would be nothing more than a mutant chimpanzee-and we do experiments on chimpanzees all the time, so the work doesn’t raise any moral questions. Right?

But surely there are a variety of questions that have to be worked through.

First, let’s think about species that don’t belong to the human family. Sometimes, recreating an extinct organism purely for scientific purposes seems perfectly acceptable. Studying a live version-say, of the 1918-19 influenza virus-might be particularly useful. It might also just be particularly interesting-we could learn whether the velociraptor had stripes-and science is motivated in part just by curiosity. Church apparently proposed that something like intellectual curiosity would justify bringing back a Neanderthal; it “would satisfy the human desire to communicate with other intelligences.” But in these cases, we don’t care what happens to the organism after we’ve learned about it, we’d keep the organism confined while we were working on it, and we’d probably kill it once we were finished. But we’d have to care about Neanderthals, and we certainly couldn’t kill them afterwards. As we know from the Geico commercials, they might be quite sensitive. And maybe they’d integrate nicely into modern urban life. Or maybe they’d be permanently unhappy, no matter where we put them up. But given these uncertainties, bringing them back to life just to satisfy our own curiosity is not justified.

Sometimes, bringing back an extinct species might be justifiable as a case of ecological restoration. But there would have to be a few caveats. First, “restoration” seems appropriate only if the extinction was caused by humans (as may well have been the case with Neanderthals). Under its usual meaning, “restoration” means that we’re trying to undo some damage we’ve done, not that we’re hoping to turn back the evolutionary or geologic clock. Also, “restoration” seems appropriate only if the recreated species would be returned to its ecological home. Recreating a species only to put it in zoos doesn’t undo damage-the animal is animated, but not “restored” to the world. And recreating a species but introducing it to a new ecological home wouldn’t count either. That would be analogous to moving an extant species from one ecosystem into another, and that’s one of the things that sometimes later makes ecological restoration necessary, because one sometimes ends up with an invasive species.

In any event, the concept of undoing environmental damage is of no help in thinking about recreating Neanderthals. The problem here concerns what we do to sentient creatures, not what we do to nature. The prospect of recreating Neanderthals is more like the “designer baby” scenario, in which we consider whether parents might choose which baby to have on the basis of nonmedical criteria-sex, eye color, or whatever is technically feasible. The difference is that, with Neanderthals, the designer baby would be a caveman.

So what of the arguments that have been offered against creating designer babies? Interestingly enough, some of them don’t apply very cleanly, even assuming they work fine for Homo sapiens sapiens. Would concern about the Neanderthal’s well-being argue against creating it? It’s certainly a concern, but it’s particularly sketchy in this case since, never having met one, we really don’t know what make Neanderthals happy. A Neanderthal alone in a sea of Cro Magnon descendants might be wretched, but also might not care.

The German philosopher Jürgen Habermas has argued that some measure of independence from the creative control of other people is necessary if a person is to feel that she is a full moral agent and a full member of the moral community. A person must feel that who she’ll be and what she’ll be like is ultimately up to her. Parents influence it heavily, by deciding what schools she’ll go to and whether she’ll try to learn an instrument, but when they begin to make adjustments to her brain and body before her birth, they’ve overstepped a line.

But even supposing this makes sense for Cro Magnon descendants, there might be special hitches in applying it to a Neanderthal. A Neanderthal might have a special Neanderthal perspective on morality and community. Maybe feeling like one is one’s own person would not be important to a Neanderthal. Maybe Neanderthal views about acceptable human interaction are not even what we’d recognize as “morality.” After all, one of the reasons it would be interesting to communicate with other “intelligences” is that we might form new views about the connection between intelligence and morality.

The bioethicist Dena Davis has argued that we should be wary about creating designer children because the children brought into the world might not have an “open future.” They would be full members of the moral community, she thinks, but they might not feel that they were adequately in command of their own life trajectories. Depending on various things-what traits were selected, what the parents’ attitudes were-they might feel constrained to become one thing rather than another. But again, who knows how to apply this to Neanderthals? The concept of an open future might be unique to Homo sapiens sapiens-it might even be unique to very modern members of our subspecies. And what would we say about the future of a newly created Neanderthal? In some ways, it might seem closed; in some ways, it might seem wide open-particularly compared to every other Neanderthal who ever lived.

There are other objections to designer babies, but you get the drift. The objections depend variously on claims about how the children would feel, how the parent-child relationship would change, what one can reasonably expect of one’s life, or what reasonable people think about human interaction. They all depend on what Paul Ehrlich called our “human natures”; they depend on the accumulated biological and cultural traits that make us who we are. And if the child in question were a Neanderthal, we can do little more than hazard some guesses. Maybe, in fact, what makes a Neanderthal think that life is worth living would be more like what makes life worthwhile to a chimpanzee than what makes it worthwhile to me.

My instinct is not to do it, in spite of the difficulty of laying out good reasons for feeling that way. We may now know enough technically to do it. But we don’t know enough to do it right.

Gregory E. Kaebnick is the editor of the Hastings Center Report and a participant in a research project led by The Hastings Center and funded by the Alfred P. Sloan Foundation on the ethical issues of synthetic biology.