Empathy describes an individual's ability to understand and feel the other. In this article, we review recent theoretical approaches to the study of empathy. Recent evidence supports 2 possible empathy systems: an emotional system and a cognitive system. These processes are served by separate, albeit interacting, brain networks. When a cognitive empathic response is generated, the theory of mind (ToM) network (i.e., medial prefrontal cortex, superior temporal sulcus, temporal poles) and the affective ToM network (mainly involving the ventromedial prefrontal cortex) are typically involved. In contrast, the emotional empathic response is driven mainly by simulation and involves regions that mediate emotional experiences (i.e., amygdala, insula). A decreased empathic response may be due to deficits in mentalizing (cognitive ToM, affective ToM) or in simulation processing (emotional empathy), with these deficits mediated by different neural systems. It is proposed that a balanced activation of these 2 networks is required for appropriate social behavior.