Why is life like a poker game? How did a failed robbery help to explain human nature? Why are we so certain bad men will win - and yet we're so wrong? In this, the third volume of The Secrets of Life quartet, SS O'Connor once more uses his easy-going, conversational style to explain how the science of decision analysis developed, and why it has come to show us not only the reasoning behind how humans arrive at their choices in life, but why so much of the apparently bizarre behaviour of the natural world has the same hard logic to it. Instead of the confusion and chaos one might expect, O'Connor lays out how the options organisms face when they interact can actually be analysed, and how we humans then refined this process through the addition of our intelligence and language skills. Starting with the extraordinary new ways of thinking that Adam Smith opened the world's eyes to, the book progresses to the 20th century - and shows how the mathematical reasoning behind our thought processes was revealed at a time when the very future of the world was at stake. From these earliest investigations, through to the fevered disagreements of later experts, this third volume of the Secrets of Life series explains how the science of game theory illuminates the reasons for our behaviour. In particular, the book provides insights into how the interests of the individual should be balanced against those of the group, and why the mechanism of trading would extend far further into our lives than we could ever have imagined. As the story unfolds it becomes ever clearer how cooperation has evolved to be the catalyst at every level of life. It explains how it was the force that built our world, and why it would settle so deeply in our hardwiring that it's become instinctive and innate in us. Perhaps most pleasingly, the same logic also shows that the benefits of collaboration are always bound to ratchet upwards - and how this will inevitably lead humans to ever-increasing levels of moral behaviour.