Magda B. Arnold's phenomenological and cognitive theory on emotions is subjected to a critical review. The theory is well-known and has inspired other theorists in the field of emotion research. However, it has generated hardly any research. At first sight this is astonishing because of its obvious qualities. Arnold does justice to the subjective nature of emotions, integrates psychological with physiological aspects, and offers a relatively simple and parsimonious theoretical model. Salient points are the conceptualization of emotions as action-tendencies, the role of appraisal in generating emotions and in emotional action, the classification of basic emotions, the explanation of increase of strength in emotions, and their organizing function or disturbing effects. A closer look into the theory, however, shows serious flaws in logical consistency and difficulties for operationalization. The authors conclude that the lack of research is partly due to the theory.