Our culture has produced the science and technology it needs to save itself. It has the wealth needed for effective action (Skinner, 1971).The "five horsemen of the modern world" are climate change, food shortages, clean water shortages, chronic disease, and obesity. Cofounder and former president of the Hastings Centera biomedical research organization-Daniel Callahan covers each of these horsemen in his new book titled: The Five Horsemen of the Modern World. Each topic has a unique history bridging the often tenuous relationship between science and public policy. According to Callahan, however, the horsemen share a single feature: Problems arising from climate change, food and water shortages, chronic disease, and obesity are getting worse despite several decades of expensive and concerted efforts to mitigate or eradicate them.Peppered with facts and vetted by experts, part one of the book reviews how we arrived at our current state. The information presented allows an interested behavior analyst to detect and understand ideological splits, relevant academic and research disciplines, specialized university programs, meetings, organizations, and pertinent journals. By providing all of this information in one location, Callahan helps anyone new to the depth of each topic to catch up quickly so they can begin to participate more fully. Behavior analysts hoping to increase their impact for any one of these problems would benefit greatly from the information in part one."Examining the pathways through the thickets" fittingly titles part two of the book. In each chapter of this section, Callahan covers familiar pathways to solving societal problems. These include increased use and advances in technology; changes in public policy, public opinion and media; and regulation via law and governance. Compounding the thickets is an ever-growing and increasingly aged population. Population dynamics exacerbate the five problems by requiring the development of novel solutions as well as demanding more from existing solutions. For behavior analysts interested in any one of the pathways, each chapter provides an overview of the disciplines that span policy and regulation, through academic research. In addition, Callahan provides substantial references to some of the current researchers and people involved with advances in technology, public policy, media, law, and governance. Where part one provided the outsider with relevant history, part two provides the outsider with current interventions and active players.