Really informative look at the what helps members of society act rationally and allows society to function. Schneier explains many of the commons models of trust that exist at different layers of society and provides examples of each. I would have preferred to have the examples be a little more in depth and most of them were covered at a very high level. I guess that would make this a good jumping off point to other books which go in depth on any of the failures mentioned in the book. Overall I really enjoyed the book it was a very easy read and I recommend it.