"Principles of Political Economy" by Arthur Latham Perry is a scientific publication written in the late 19th century. This work explores the fundamental principles of political economy, particularly emphasizing the intricacies of buying and selling, as well as the role of value in economic transactions. Perry strives to dislodge traditional concepts of "wealth" in favor of a more scientific and relatable understanding focused on "value" and its applications in human interactions and economies. The opening of the book introduces the foundations of political economy by framing the essential questions surrounding the nature of its subject. Perry describes a methodical approach to understanding economics through observations of trade in bustling environments like cities and factories, showcasing three primary categories of valuable exchanges: commodities, personal services, and credits. He argues that understanding the nature of "value"—which is defined through mutual exchanges—is crucial to appreciating the mechanics of economics. Perry sets the stage for a detailed examination of how various economic transactions reflect broader societal relationships, ultimately positioning "principles" as the core component of the political economy he aims to elucidate. (This is an automatically generated summary.)