The mission of "Communication Education" is to publish the best research on communication and learning. Researchers study the communication-learning interface in many ways, but a common approach is to explore how instructor and student communication can lead to better learning outcomes. Although scholars have long classified learning into three domains--cognitive, affective, and behavioral--it is not often that behavioral learning is investigated in instructional communication research. Thus, the focus of most of the research in instructional communication is on cognitive and affective learning. This forum explores the study of affective learning by addressing two critical questions that define the field's exploration of the topic: (1) What is affective learning?; and (2) How should we measure affective learning in instructional communication research? This forum initiates conversation on this topic. The essay presented is one of seven in this forum on the topic of affective learning. How is it possible that after more than four decades of thoughtful instructional communication scholarship, the discipline continues to advance relatively incomplete knowledge claims associated with the affective learning construct? The affective learning paradox, as explicated in this essay, may be difficult to explain, but the common themes and related insights should allow the growth as a discipline if there is an open mind in the approach to understanding the paradox and if there is a willingness to conceptually disentangle affective learning from other related constructs (e.g., student affective experiences, satisfaction, attitudes, etc.). A series of recent studies, published by political scientists, provides evidence that strongly held incorrect beliefs cannot be changed simply by disputing facts, and any idea that contradicts knowledge claims that have long been held as important can result in problems where, despite correction attempts, presenting hardline denialists with the facts just makes them dig their heels in deeper. This essay advances the conversation about important long-held beliefs by reflecting on four common themes inherent in the affective learning paradox: (1) Conceptual and Theoretical Confusion; (2) Content Validity and Poor Conceptual Fit of Existing Measures; (3) Integration of Affective Learning with Other Learning Domains; and (4) New Opportunities for Exploration and Expansion. [For the other essays in this forum: (1) FORUM: Affective Learning. Affective Learning: Evolving from Values and Planned Behaviors to Internalization and Pervasive Behavioral Change, see EJ1083005; (2) FORUM: Affective Learning. Pursuing and Measuring Affective Learning Objectives, see EJ1083008; (3) FORUM: Affective Learning. Reclaiming Affective Learning, see EJ1083012; (4) FORUM: Affective Learning. Students' Affective Learning as Affective Experience: Significance, Reconceptualization, and Future Directions, see EJ1083014; (5) FORUM: Affective Learning. Affective Learning from a Cognitive Neuroscientific Perspective, see EJ1082999; and (6) FORUM: Affective Learning. Reconsidering the Conceptualization and Operationalization of Affective Learning, see EJ1083010.]