In this commentary, I briefly present in chronological order several historical developments which can explain some of the confusions with respect to arousal that have become entrenched in the contemporary debate. These historical developments include: Immanuel Kant's eighteenth-century division of the affects into sthenic vs. asthenic; the emergence of modern conceptions of pleasure and displeasure in the West; the nineteenth-century alignment of pleasure and displeasure with “sthenic” and “asthenic” in psycho-physiology; the early-twentieth-century disruption of this nineteenth-century alignment; the establishment of (...) a new-physiological order of emotions; and the emergence of “emotional excitement” as the new feeling of the new emotion order of physiology. (shrink)