Emotion is an increasing influential area of research in psychology, political psychology, political science and other social sciences. Research is best when driven by theory because the absence of theory generates research that is subject to vagaries of meaning, interpretation, and lack of coherence, study to study. In brief, theory provides essential foundations that enable scientific explanations to be rigorously tested. As I demonstrate below, absence of, or reliance on, incomplete theories have generated results that are demonstrably flawed. I evaluate the extent to which current emotion research programs rely on a full blown theory. The programs under consideration, in alphabetical order, are: appraisal theories in psychology and political science; emotion regulation; and, valence based accounts. After a brief overview of the elements, individually and collectively, that constitute a theory of emotion. I find this worthy ambition awaits fulfillment.