FORTUNE -- Rupert Murdoch's decision to demote his own son is a perfect example of why he's endlessly interesting. Sometimes he makes business decisions purely with his head, canny and shrewd, occasionally ruthless. That's what he did this time. But sometimes he makes giant decisions with his heart, appearing misguided or just nuts; for example, he runs the New York Post and the Times of London at deep losses that will apparently continue forever, and he just doesn't care. Overall, the Murdoch method has worked well for him. For investors in his News Corp. (NWS), it has not worked nearly as well as it should have. Recent events show the problem clearly. Amazingly, amid the U.K. phone hacking scandal that led to James Murdoch's downfall -- a mushrooming story that a member of Parliament yesterday called "the single largest corporate corruption case in this country for more than 250 years" -- the Murdoch method is still working, at least for him. James was, among other things, chief of News International, the News Corp. division that owns the company's British newspapers. When the phone hacking scandal erupted at one of them, the News of the World, Rupert made one of his famously tough-minded decisions, abruptly closing the 168-year-old paper. News Corp.'s value dropped by billions of dollars as investors feared more revelations would follow.