This advanced course will introduce students of applied behavior analysis to radical behaviorism, defined as the philosophy of the science of behavior. Students will study the basic assumptions and presuppositions (e.g., the philosophical debate between free will and determinism) about what counts as behavior and its causes. Students will examine the role of verbal behavior in environment-based (i.e., variations of behavior analysis) and organism-based (i.e., mentalism and cognitivism) interpretations ad explanations of behavior. This will bring us to the root of many complex abstract and theoretical issues, such as interpreting the behavior of self and others, mentation, society, culture and behavioral resonsibility, ethics, rights and values. Students will address these issues in terms of their implications for ABA practitioners in their everyday work. The course will give historical perspective to the evolution and substance of radical behaviorism, and how it compares to other conceptual systems.