The Encyclopaedia Britannica (1999 edition) defines empathy as:"The ability to imagine oneself in anther's place and understand other's feelings, desires, ideas, and actions. It is a term coined in early 20th century, equivalent to German Einfühlung and modelled on "sympathy." The term is used with special (but not exclusive) reference to aesthetic experience. The most obvious example, perhaps, is that of actor or singer who genuinely feels part he is performing. With other works of art, a spectator may, by a kind of introjection, feel himself involved in what he observes or contemplates. The use of empathy is an important part of counselling technique developed by American psychologist Carl Rogers."
Empathy is predicated upon and must, therefore, incorporate following elements:
Imagination which is dependent on ability to imagine; The existence of an accessible Self (self-awareness or self-consciousness); The existence of an available other (other-awareness, recognizing outside world); The existence of accessible feelings, desires, ideas and representations of actions or their outcomes both in empathizing Self ("Empathor") and in Other, object of empathy ("Empathee"); The availability of an aesthetic frame of reference; The availability of a moral frame of reference. While (a) is presumed to be universally available to all agents (though in varying degrees) - existence of other components of empathy should not be taken for granted.
Conditions (b) and (c), for instance, are not satisfied by people who suffer from personality disorders, such as Narcissistic Personality Disorder. Condition (d) is not met in autistic people (e.g., those who suffer from Asperger syndrome). Conditions (e) is so totally dependent on specifics of culture, period and society in which it exists - that it is rather meaningless and ambiguous as a yardstick. Condition (f) suffer from both afflictions: it is both culture-dependent AND is not satisfied in many people (such as those who suffer from Antisocial Personality Disorder and who are devoid of any conscience or moral sense).
Thus, very existence of empathy should be questioned. It is often confused with inter-subjectivity. The latter is defined thus by "The Oxford Companion to Philosophy, 1995":
"This term refers to status of being somehow accessible to at least two (usually all, in principle) minds or 'subjectivities'. It thus implies that there is some sort of communication between those minds; which in turn implies that each communicating minds aware not only of existence of other but also of its intention to convey information to other. The idea, for theorists, is that if subjective processes can be brought into agreement, then perhaps that is as good as (unattainable?) status of being objective - completely independent of subjectivity. The question facing such theorists is whether intersubjectivity is definable without presupposing an objective environment in which communication takes place (the 'wiring' from subject A to subject B). At a less fundamental level, however, need for intersubjective verification of scientific hypotheses has been long recognized". (page 414).
On face of it, difference between intersubjectivity and empathy is double:
Intersubjectivity requires an EXPLICIT, communicated agreement between at least two subjects. It involves EXTERNAL things (so called "objective" entities). These "differences" are artificial. This how empathy is defined in "Psychology - An Introduction (Ninth Edition) by Charles G. Morris, Prentice Hall, 1996":
"Closely related to ability to read other people's emotions is empathy - arousal of an emotion in an observer that is a vicarious response to other person's situation... Empathy depends not only on one's ability to identify someone else's emotions but also on one's capacity to put oneself in other person's place and to experience an appropriate emotional response. Just as sensitivity to non-verbal cues increases with age, so does empathy: The cognitive and perceptual abilities required for empathy develop only as a child matures... (page 442)
In empathy training, for example, each member of couple is taught to share inner feelings and to listen to and understand partner's feelings before responding to them. The empathy technique focuses couple's attention on feelings and requires that they spend more time listening and less time in rebuttal." (page 576).
Thus empathy does require communication of feelings AND an agreement on appropriate outcome of communicated emotions (=affective agreement). In absence of such agreement, we are faced with inappropriate affect (laughing at a funeral, for instance).
Moreover, empathy does relate to external objects and is provoked by them. There is no empathy in absence of an empathee. Granted, intersubjectivity is intuitively applied to inanimate while empathy is applied to living (animals, humans, even plants). But this is a difference in human preferences - not in definition.