Hypergraphia, about which I knew nothing prior to reading this book, is the medical term for an over-powering desire to write. Writing, Dr. Flaherty tell us, is the domain of the cerebral cortex, but the desire to write is the domain of the limbic system -- the hypothalamus and the structures of the temporal lobe. It is altered temporal lobe activity that is associated with creativity. On the other hand, frontal lobe processes are involved in writer's block. This area, as science, struck me as new and very much evolving. The most interesting section of the book, even more speculative than the location of writing proclivities, is her commentary on the inner voice and its role in writing. This is an area where strands fuse -- religion, creativity, psychosis. For Dr. Flaherty it was one morning "that bristled with significance. The way a crow flapped its wings as it rose heavily off the ground was a semaphore, signalling something just past my understanding." And not long after she heard, "the opposite of writer's block," her signal to write about hypergraphia. This internal/external presence of a voice became manifest to her following a depression brought on by the death of twin infants. Remarkably, if not miraculously, she later gave birth to another set of twins, thriving at the time of her writing. This is an unusual book. She interweaves her personal history and her clinical training. Coupled with a wide and diverse reading, Dr. Flaherty demonstrates in this book an intense mind; reading her is like riding with a mind in over-drive. I look forward to her next book, and she has all but assured us that one is in the making.