An extraordinary book, worth reading by anyone interested in innovation, entrepreneurship, and technological change. The book shows lucidly and with ample evidence that talk is increasingly dissimilar to walk in current business ventures. Serious doubt is healthy and rational, as exercised in Jeff’s book. He shows that we are now in the middle of a perfect storm created by the oversupply of cheap money looking for investments in a marketplace of ideas where many false visionaries sell shallow promises and hype in all forms. For sure, progress will happen, but more slowly, and rarely as predicted by the prophets of hype. And progress will also have negative side-effects, such as the rise of fake information, polarization, threats to privacy, bio-threats, and ultimately the danger of the collapse of democracies and markets.