Book Five begins with a clarification on the expenses of maintaining both militias and standing armies; Book Two details the "nature, accumulation, and employment of stock;" and Book Four details the "systems of political economy."  
Among the situations the author uses to make his points in this book are the plight of Irish prostitutes in London and the exploitation of Holland's fisheries.  Book Five begins with a clarification on the expenses of maintaining both militias and standing armies; Book Two details the "nature, accumulation, and employment of stock;" and Book Four details the "systems of political economy."  Its author advocated that government maintain a laissez-faire attitude and coined the principle of the "invisible hand" to elucidate this point.  FTP, name this magnum opus of Adam Smith.
Among the situations the author uses to make his points in this book are the plight of Irish prostitutes in London and the exploitation of Holland's fisheries.  
An Inquiry into the Nature and Causes of the Wealth of Nations