To the extent that consciousness is useful, it is useful in small quantities, and for very particular kinds of tasks. It's easy to understand why you would not want to be consciously aware of the intricacies of your muscle movement, but this can be less intuitive when applied to your perceptions, thoughts, and beliefs, which are also final products of the activity of billions of nerve cells.
David's iPad app "Why the Net Matters, or Six Ways to Avert the Collapse of Civilization" was recently called a "superbook" by the New York Times Magazine. For a taste of the argument, read David's article in WIRED or watch a video of his talk at the Long Now Foundation. Don't have an iPad? The manuscript is now available as an eBook.
In September, 2009, Sum became the number 2 book in the United Kingdom on Amazon's bestseller list, only behind Dan Brown's Lost Symbol.
Sum was selected as Book of the Week by both The Guardian newspaper and The Week newsmagazine.