Therapeutic cloning

If reproductive cloning has few friends -- aside from some renegade scientists and cultists who insist they'll use it to help infertile couples -- a related technology poses much tougher ethical questions.

Therapeutic cloning does not strive to make whole humans. Instead, it makes embryos as a source of embryonic stem cells for therapeutic purposes. Because embryonic stem cells can grow into any body cell, they might be cultured into nerve cells, skin cells, even hair follicles for the bald. The obvious use of therapeutic cloning would be treating deadly diseases like diabetes and Parkinson's, where a specific type of cell has died. It's a good bet that replacing those cells would restore health.

Therapeutic cloning research would end in this country, however, if restrictive legislation passes the Senate. Sen. Sam Brownback, for example, writes that "The prospect of creating new human life solely to be exploited and destroyed in this way has been condemned on moral grounds by many as displaying a profound disrespect for life."

But society is already willing to tolerate the death of lab-created embryos during in-vitro fertilization, says medical ethicist Dan Wikler. "Anyone who would says we should not embark on this kind of therapeutic cloning would, on pain of inconsistency, be opposed to routine IVF, where embryo are created in advance, with big chance of being destroyed as surplus."

Wikler maintains that the quest to save existing lives deserves moral standing. "Anyone who would says that the chance to save a life through therapeutic cloning is wrong, would have to explain why they have not been upset by the practices that go on under IVF, which is basically the same thing."