Ingenuity comes in two forms - technical and social. One without the other will not provide us with lasting solutions. Technical solutions might even lead us down a garden path without complementary social ingenuity. It is the latter that guarantees results taking economic, ecological and cultural needs into account. To make his point, Homer-Dixon explores a wide range of examples demonstrating tremendous levels of ingenuity at work all over the world - both technical and social. His contention is that they are available to us if we look properly.

H-D, or Tad as he is usually called, takes us on a tour around the planet, using concrete examples to amplify his argument. Obviously, the result is not your usual travelogue and we are not visiting popular vacation spots or tourist attractions. Visiting Vegas, London's Canary Wharf or Patna, India, he believes that a personalized approach facilitates the following of his arguments. While some reviewers have criticized that H-D places himself too much into the story, it nonetheless contributes to the readability of the often exceedingly complicated issues he is addressing. He also conveys his own learning through interviews with some of the foremost scientists in the various fields he covers: from soil scientists to climatologists, from computer science to economy and architecture.

His in depth deductions from the wide range of interviews with scientists represent one of the highlights of the book. For example, while exploring the latest research into the human brain as the central point for ingenuity development, Tad takes his questions to one of the world's leading experts on frontal lobes, Donald Stuss. His conversations with Stuss provide fascinating insights in the importance of frontal lobe abilities to process change and integrate experiences and learning. This part of the brain handles our creative and intellectual capabilities. With aging, the ability of the brain to absorb new information lessens while the ability to digest and process complex interrelationships increases. His conclusions are far reaching - changing the way we assess leadership and identify those who are best qualified to meet the challenges of our corporate and administrative hierarchies. After each of these in-depth conversations, H-D reflects on the substance of the dialogue and returns to his overall theme - how can we minimize the ingenuity gap that is widening all the time.

Tad groups his book into sections, each addressing different aspects and disciplines from which to review the ingenuity requirements of the modern world. He depicts environmental problems and those related to continuing rapid population growth, which to him is a major challenge for the planet's future. He does not have a lot of patience with the 'economic optimists' or the 'techno-hubris'. He expands on incidences which demonstrate that a single-minded and, in some way, naïve belief that technological advance alone is capable of solving the world's problems will fail.

It's impossible to do justice here to the many strands of global analysis that Homer-Dixon presents the reader with. His many years of research, in particular into environmental scarcity and civil violence allow him to assess ingenuity gaps from many different angles. The criticism that he does not supply adequate answers and does not show a way forward, is oversimplifying what H-D is attempting to achieve. The modern world is at a level of complexity that no one person can comprehend. As a consequence, it will take the ingenuity and political will of many to address the wide range of issues confronting us. In the pursuit of answers, he urges intellectual humility and thinking outside the box. He encourages his readers to take up the challenges, explore them further, and question any simple or easy solutions being offered by political leaders. This is an important reference book to be read more than once.