Six decades ago, a 21-year-old Navy fighter pilot on a mission over the Pacific was shot down by Japanese artillery. His name might have been forgotten, were it not for 6-year-old James Leininger. Quite a few people — including those who knew the fighter pilot — think James is the pilot, reincarnated. James' parents, Andrea and Bruce, a highly educated, modern couple, say they are "probably the people least likely to have a scenario like this pop up in their lives." But over time, they have become convinced their little son has had a former life. From an early age,...