This is a fun survey of the science of trolleyology and thus ethics. The trolley problem has intrigued as much as baffled, psychologists, philosophers, ethicists, and neuroscientists for almost half a century. This, occasionally tongue in cheek, story of the history of one of the most fundamental questions in ethics (Is the life of the single individual worth less than a larger group of people?) is edifying and entertaining. I was amazed at the many variations of the problem as presented to subjects. It is fun to pose the variations of the fundamental problem to people and see where they "draw their line." Armchair philosophers and ethicists will find this book thought provoking.