Sympathy and empathy are complex and entwined concepts with philosophical and scientific roots relating to issues in ethics, aesthetics, psychology, biology, and neuroscience. For some, the two concepts are indistinguishable, the two terms interchangeable, but each has a unique history as well as qualities that make both concepts distinct. Although each is associated with feeling, especially the capacity to feel with others or to imaginatively put oneself “in their shoes,” the concepts’ sometimes shared, sometimes divergent histories reveal more complicated origins, as well as vexed and ongoing relations to feeling and emotion and to the ethical value of emotional sharing. Though empathy regularly is considered the more advanced and egalitarian of the two, it shares with sympathy a controversial role in historical debates regarding questions of an inborn or divine moral sense, prosocial behavior and the development of human communities, the relation of sensation to unconscious mental processes, brain matter, and neurons, and animal/human difference. In literary criticism, sympathy and empathy have been key components of aesthetic movements such as sentimentalism, realism, and modernism, and of literary techniques like free indirect discourse (FID), which are thought (by some) to enhance readerly intimacy and closeness to novelistic characters and perspectives. Both concepts have also received their fair share of suspicion, as the capacity to feel, or imagine feeling, the emotions of others remains a controversial basis for ethics.