James–Lange theory influenced a century of emotion research. This article traces the theory's origins in philosophical psychology, considers differences in the thinking of James and Lange, and assesses Cannon's early critique and the resulting debate. Research is reviewed evaluating physiological patterns in emotion, the discordance of reported feelings and visceral reactivity, and the role of generalized arousal. NeoJamesian theories of attribution and appraisal—and alternative views based on dynamic psychology—are critically examined. A conception of emotion is presented, on the basis of developments unknown to James in conditioning theory, information processing, and neuroscience. Computational models of mentation are discussed, and implications are drawn for the classical debate on cognition and emotion. In concluding, new paths for emotion research are outlined and homage paid to the inspiration of William James.