WHEN Andrea Pia Yates drowned her five children because, she claimed, she wanted to save them from hell by killing them in the innocence of their youth, it was either mental illness or cold-blooded murder. Certainly, it was a misguided application of the Christian faith Yates practiced. Her crime seemed like a clear result of mental illness to me. To jurors who evaluated the evidence, it sounded like murder, and they sentenced her to life in prison. When 15 schoolgirls burned alive in March because religious police in the Saudi Arabian city of Mecca prevented them from fleeing a blazing...