"Why do we do what we do?" This may seem like a simple question at first; in practice however, the closer we examine where our decisions come from, the less intention and independent reasoning we find. Instead, we find primitive instincts and ideas that are often based on nothing more than the imagination of someone who has been dead for centuries. 

The first part of this book focuses on drivers of decisions that we are born with - our inborn knowledge. It discusses the brain, evolution of instincts, and the social instincts that prominently rule our lives. 

The second section focuses on learned knowledge which guides our behaviors - our ideas. It delves into imagination, learning, model thinking, and language. It discusses the framework of our thinking that is determined by culture, including authority and belief. 

The third and final section focuses on independent knowledge that we generate through reason. This section discusses the process of reasoning, the idea of principled models and their role in technology, the application of reasoning in society, and considerations for purpose finding meaning in life. 

The last chapter discusses the idea of a personal culture, one untethered from nature and culture, that serves to maximize the potential for humanity's future.