Memories make us who we are—even, or perhaps especially—the painful ones. What would life be like if we could erase their emotional associations? It's not just a hypothetical question; scientists are finding that the drug propranolol, originally developed for hypertension, can prevent posttraumatic stress disorder if taken soon after a stressful event—or even reduce symptoms decades later if taken during therapy sessions. The drug works by blocking adrenaline, whose release helps solidify memories. But the intervention is ripe for misuse, and its effects on personality (will it blunt happy thoughts too?) are yet unclear.

Would you use a drug to dampen an emotional memory?

NO: I'm not categorically against it for treating serious disorders, but it's a crude method and we don't yet appreciate the depth and complexity of personality. I favor an authentic personal process whereby we gain insight and strength of character through encounters with the struggles of human life. Just imagine the range of uses: forgetting shameful, unethical, or even violent actions. I suppose most of us would like to forget some things from our high school years, but would that make us better adults? We "forget" painful experiences by subsuming them under a larger positive purpose. —William Hurlbut teaches biomedical ethics at Stanford and serves on the President's Council on Bioethics.

YES: I've heard from countless people telling me that they would do anything to rid themselves of PTSD. No one has written to tell me they'd like to dampen the memory of an embarrassment, a guilty act, or a mildly emotional experience. We routinely try to dampen the impact of emotional experiences with cognitive therapy or benzodiazepines. The only thing novel about propranolol, based on our laboratory studies with animals and humans, is that this drug can weaken the formation of new memories. But otherwise, such a treatment should be considered alongside any treatment aimed at reducing severe anxiety. —James McGaugh studies neurobiology and behavior at the University of California at Irvine.