Making scientific history is hard enough. It's tougher still when a lot of people wish you hadn't. That was the problem facing Woo Suk Hwang and Dr. Shin Yong Moon of Seoul National University when they announced in February that they had cloned human embryos for the first time. With that development, a medical and ethical door that had remained mostly closed was kicked wide open.
The researchers' method was familiar to anyone who has been following the cloning parade from sheep to mice to other animals over the past several years. After harvesting 242 eggs from 16 female volunteers, Hwang...