that even when the external object of perception has departed, the impressions it has made persist, and are themselves objects of perception; and let us assume, besides, that we are easily deceived respecting the operations of sense perception when we are excited by emotions, and different persons according to their different emotions; for exam ple, the coward when excited by fear, the amorous person by amorous desire; so that, with but little resemblance to go upon, the former thinks he sees his foes approaching, the latter, that he sees the object of his desire; and the more deeply one is under the influence of the emotion, the less similarity is required to give rise to these impressions.