Phenomenology and Modern Behavioral Psychology Lindsay B. Fletcher (bio) and Steven C. Hayes (bio) Keywords acceptance, contextualism, defusion, relational-frame-theory Pérez-Álvarez and Sass (2008) deserve praise for examining the philosophical roots of clinical psychological science. Modern psychology has moved away from the development of philosophy and theory that is needed to ground scientific investigation within a coherent system. The result is increasingly ill-defined constructs and research programs that each operate within their own divergent paradigm. B.F. Skinner is one of the few modern experimental behavioral psychologists who attempted to build a coherent science of behavior based on observable events with testable hypotheses. Acceptance and Commitment Therapy (ACT; Hayes, Strosahl, and Wilson 1999) and its associated basic science of cognition, Relational Frame Theory (RFT; Hayes, Barnes-Holmes, and Roche 2001), build on Skinner’s work to produce a more progressive science. Psychology and philosophy are different disciplines and how they are approached is defined by the objective. The purpose of philosophy from a scientific point of view is not the same as from a philosophical point of view. It is fine to compare radical behaviorism and phenomenology, but it seems important to ask whether and how this will lead to a more progressive science of behavior. In this commentary, we discuss the philosophy and theory that underlie ACT/RFT and show how they reflect on the relevant points made by the authors regarding the shared features of phenomenology and radical behaviorism. We make two adjustments to the explanation of radical behavioral concepts presented in the current paper to create a more coherent analysis. Finally, we show here how the development of a theory based on applied goals directly informs the methods used in clinical settings. Philosophical Assumptions The field of behavior analysis that originated with Skinner has different strands. Some are holistic and pragmatic, whereas others are elementalistic and mechanistic (Hayes, Hayes, and Reese 1988). ACT is based on an a-ontological philosophy termed functional contextualism (Hayes 1993), which views behavior analysis from a holistic and pragmatic perspective. Functional contextualism (AKA radical behaviorism) shares some of the assumptions of phenomenology, as has long been noted (Day 1969). For example, Pérez-Álvarez and Sass (2008) identify a-dualism, or monism, as a common feature. In functional contextualism, the whole is divided into functional units for the purpose of prediction and influence. A three-term contingency (antecedent–behavior–consequence) in behavior analysis is viewed as a [End Page 255] whole event with pragmatically distinguishable aspects, not an assemblage. As the authors point out, this results in a dialectic tension between stimulus control, action, and reinforcer because none are distinct units, and each is defined with reference to the others much as the front of a coin cannot exist without the back. These are not ontological entities, but functional units that are abstracted from the whole for pragmatic purposes. What is “radical” about radical behaviorism is that the philosopher, psychologist, or researcher participates in the event they are observing, and their own acts of scientific observation are identified based on their own functional properties. Behavioral Thinking In the service of further developing this philosophical and theoretical foundation and considering it along side phenomenology, we need to examine two aspects of the target article. The first regards the role of the environment in shaping behavior that is central to behavioral and contextual theories. The authors object to behaviorism’s notion of environment and suggest replacing it with the concept of the world, stating that “animals have environment, but man has world.” What is missing is an account of that shift. We believe that modern behavior analysis provides that account. Similarly, the paper argues that “reinforcers are not just things that follow behavior, but also, and above all, values that guide our life.” Again what is missing is an account of the precise behavioral basis for the distinction. In an attempt to do this, the authors incorrectly analyze operant behavior as future oriented, even appealing to final causality. In the three-term contingency, the discriminative stimulus sets the occasion for reinforcement of a particular behavior. The behavior of interest has been reinforced in similar contexts in the past, which gives...