Free imagination is the inestimable prerogative of youth and it must be cherished and guarded as a treasure. So said Felix Bloch, the physicist who won a Nobel Prize in 1952. But is the imagination truly cherished (let alone guarded) in a culture where young people are over-supervised, under-exposed to nature, and - when they're not being herded to organized activities - generally sequestered in front of TVs and computers? Are their imaginative powers being stifled right from the start? Jeannine Ouellette explores these and other questions in "The Death and Life of American Imagination."