"An idea is only an idea if it causes unease, debate and reflection. By that standard, Thomas Homer-Dixon's concept of an 'ingenuity gap' is truly a new idea. I can think of no other new concept that so fully condenses all of the challenges we face as a human civilization than the 'ingenuity gap'. Homer-Dixon has found a way to unite all of our concerns about economics, war, population growth, complexity, etc. under a single heading. He is one of an elite group of academics who can write for a mass audience."