Empathy has become a subject of much interest. It's of interest in fiction as we feel for characters in stories, in politics as we wonder what to feel for people in different social groups, and in history as we wonder about the emotions of people living in societies of the past.
The word "empathy" only entered European languages about a hundred years ago. Before that--in English at least--it was contained within the wider concept of sympathy.
Now empathy is best thought of in the way described by Frederique de Vignemont and Tania Singer (2006) as:
(a) having an emotion, that
(b) is in some way similar to that of another person, that
(c) is elicited by observation or imagination of the other, and that involves
(d) knowing that the other is the source of one's own emotion.
As de Vignemont and Singer explain, there's now been a range of demonstrations using functional Magnetic Resonance Imaging (fMRI), in which areas of the brain activated by experiencing an emotion in oneself have been found to be the same of those activated when one observes or imagines an emotion in someone else.
Sympathy in its modern-now more specific-meaning is having some feeling for the predicament of another person and being moved by this predicament, for instance towards helping the person. The older idea of sympathy included both feeling emotions like those of someone else and feeling for that person's predicament.
Engaging with fiction is an empathetic act. It involves entering a simulated social world, and inserting characters' goals and plans into the processor that we usually use to make and carry out our plans in the world. It has two parts. In the first, we set aside our own plans and concerns for a while as we take up our book; we then take on the plans and concerns of a fictional character, and empathetically imagine what that character might feel. We are not just book-reading, we are mind-reading. In the second part, we experience emotions--our own emotions--in the circumstances of a character's concerns, plans and actions.
History, too, is typically written in narrative form, and here we do something similar. We imagine ourselves into societies of the past, imagine what it must have been like, perhaps, to have sailed with Columbus, or imagine what it must have been like as native Americans to see strangely clad men coming ashore with their steel weapons. For we shouldn't think of fiction as something that has been been merely constructed (though of course novels and films are constructed) as opposed to derived from evidence (in the way that science and history are). Rather, we should think of fiction in terms of its subject matter-narratives of human intention that don't all come out as expected. And this, too, isn't a bad way to describe social history. Fiction-writers usually spend a great deal of time doing research to make sure that settings and attitudes of characters are right for these settings.
When in life or in narrations, plans and actions don't come out as expected, the results are usually emotions. It's these emotions, empathetically experienced, that are entrance-ways into the imagined worlds of novels and films, or of the past.
De Vignemont, F., & Singer, T. (2006). The empathetic brain: How, when, and why. Trends in Cognitive Sciences, 10, 435-441.
Image: fMRI result on empathy from Singer et al. (2004)