On its back cover, "The Secret" boasts that great thinkers like Plato, Galileo, Edison and Einstein all knew a secret that the rest of us didn't know. Green doesn't buy it. "Look, I've never met any of those guys," he said, "but I have zero evidence that any of them would've held on to any fundamental secret about the world and not shared it."
The final skeptic of "The Secret" was Dr. Louis Aronne, one of the nation's foremost authorities on weight loss. He sees a silver lining, but he still has his doubts. "All in all, I think that there are some aspects of this that can be helpful," said Aronne. "It's very important to think positively if you want to achieve anything."
"I think that's one aspect of this that could be very helpful. But one of the problems we've had in the area of weight control is the idea of magical thinking. And this is almost the perfect example of magical thinking."
"The Secret" has been successful in blending science and faith in a way that readers and viewers can easily follow, and, despite the doubts expressed by many critics, it's no secret that many Americans are eager to learn more. ABC News' Eric Johnson contributed to this report.