<p>Hayes and Fryling's book <i>Interbehaviorism: A Comprehensive Guide to the Foundations of Kantor’s Theory and Its Applications for Modern Behavior Analysis</i> is an updated account of Kantor’s interbehaviorism for behavior analysts. Their book reflects on current theoretical, empirical, and applied developments in behavior analysis while developing Kantor’s position on science, the scientific enterprise, and the psychological field. To achieve this, the authors organize their book into a philosophical and theoretical section in which the main postulates of Kantor’s interbehaviorism are presented and shown to enhance current analysis. In the second part, they present Kantor’s perspectives on linguistic behavior, inapparent events, memory, the self, perspective-taking and relationships, feelings, human development, family values, and morality, while contrasting them with traditional psychology and Skinner’s perspectives. Some chapters provide more tools for connecting theoretical accounts to applied and basic practice, whereas others serve as an appetizer for future developments. Given the complex nature of Kantor’s proposal, this is a book to be studied and is suited for researchers, advanced students, and practitioners interested in theory. It may be used as a required reading for any class on theoretical and philosophical aspects of behavior analysis. The book serves as a reference to current developments in Kantor’s interbehaviorism, while offering tools for study and the necessary philosophical and theoretical tools to address some of the most common critiques of behavior-analytic explanations of complex behaviors.</p>