The language problem begins when infertile John and Jane visit a clinic, where John's sperm and Jane's eggs are removed from their bodies. Scientists then coax the sperm into 10 eggs, which at that point become "embryos," that is, the first stage of human life. Five of these embryos are placed in Jane's womb, with the hope that at least one will mature into a "fetus" (the next stage of human life). This procedure is called in vitro fertilization. What happens to the other five prefetal human beings? They are either frozen for possible later use (in case Jane's body rejects the first five), or they are simply tossed into a Dumpster—how many each year, nobody knows, but it likely ranges in the tens (if not hundreds) of thousands. This strikes almost everybody as a great tragedy, but for alarmingly different reasons. Christianity Today objects to the callous destruction of human life. Superman star Christopher Reeve—who has been paralyzed since 1995—is horrified by the waste, arguing that it is a pity because these embryos, which contain some perfectly good stem cells, could be put to good use.

"Is it more ethical for a woman to donate unused embryos that will never become human beings," he reasoned before the Senate subcommittee debating stem-cell research, "or to let them be tossed away as so much garbage when they could help save thousands of lives?"

Stem cells are the cells from which all 210 different kinds of human tissue originate. Stem cells taken from embryos (versus adults) are especially effective at maturing into any tissue, and thus can heal or restore diseased tissues. Thus some scientists believe that cures for heart disease, Alzheimer's, Parkinson's, and other afflictions may be in sight.The government currently ...