Every generation takes for granted beliefs or practices that strike later generations as unconscionable. Just try explaining to your children public executions, chattel slavery, or eugenics. Your offspring will gape, stunned, until it dawns on them that the society you’re raising them to take part in has an astonishing capacity not to think things through. So, what’s not being thought through right now? The competition is stiff: the continued use of fossil fuels when catastrophic storms batter our shores, feeding our children off toxin-leaching plastic tableware, etc., etc.

You’d think that the professionals most likely to predict our regrets would be statisticians, trained as they are to rank the likelihood of negative outcomes. But prognostication of this sort is more gift than skill, since you need a finely tuned moral sensor as much as, if not more than, advanced numeracy. You can’t say what history will deem barbaric unless you feel a punch in the stomach every time you encounter it. This is why it was a novelist, not a statistician, who first sounded the alarm—for me—about a fast-tumbling cascade of changes I hadn’t thought hard about before.

The novelist is Margaret Atwood. What she made me think about is bioengineering. She’s not the first to worry about it, goodness knows. You can take your pick of Cassandras: Michael Crichton, Mary Shelley, whoever made Gattaca. Literature and pop culture never stop obsessing about the bastard spawn of technology and biology, although movies love to have it both ways, wallowing happily in high-tech gadgetry even as they deplore its effects.

Feverish as all this artistic angst is, what’s remarkable is that it barely keeps pace with reality. We are hurtling ever faster toward a point of no return. Consider that, just earlier this year, MIT researchers managed to implant false memories in mice. Or that the now-common procedure of preimplantation genetic diagnosis (PGD) lets would-be parents in fertility treatment test their multiple embryos for defects and discard the embryos they don’t want. One of these days, we may also be able to slow down aging by stopping the degradation of telomeres. (Telomeres are the caps on the ends of chromosomes that keep them from fraying.)

Let’s assume we really are approaching the state of what some people call transhumanism and others call posthumanism, where bioengineering will have winnowed out disease, dimwittedness, madness, old age, and—why not?—death. Would that be a bad thing? Reason magazine’s Ronald Bailey doesn’t think so. He celebrates it as “liberation biology”—liberation in the libertarian sense, “a biotechnological future determined by the choices and decisions of individuals who want to use technology to help themselves and their families live richer, fuller lives.” The naysayers disagree. (They always do.) Philosophers and environmentalists such as Jürgen Habermas, Francis Fukuyama, and Bill McKibben—Bailey dismisses their kind as bioconservatives—think that all these individual choices will add up to a large and dangerous one for humanity as a whole. Take PGD, which may eventually allow us to manipulate genes for enhanced intelligence or beauty just as easily as we can now weed out defective ones. The anti-bioengineering contingent has a few problems with this. First, pre-programming by parents violates the freedom of children to cultivate their talents as they see fit; there’s an important psychological difference between having superb visual-spatial reasoning because nature gave it to you and having it because your parents thought it would help you get into MIT. Second, this kind of tinkering with genetic material, affordable to some, unattainable by others, risks wiping out the notion of a shared humanity, with potentially grave political results. How would it change our understanding of the Declaration of Independence if all men (and women) weren’t created equal?