The concept of empathy has received much attention from philosophers and also from both cognitive and social psychologists. It has, however, been given widely conflicting definitions, with some taking it primarily as an epistemological notion and others as a social one. Recently, empathy has been closely associated with the simulationist approach to social cognition and, as such, it might be thought that the concept’s utility stands or falls with that of simulation itself. I suggest that this is a mistake. Approaching the question of what empathy is via the question of what it is for, I claim that empathy plays a distinctive epistemological role: it alone allows us to know how others feel. This is independent of the plausibility of simulationism more generally. With this in view I propose an inclusive definition of empathy, one likely consequence of which is that empathy is not a natural kind. It follows that, pace a number of empathy researchers, certain experimental paradigms tell us not about the nature of empathy but about certain ways in which empathy can be achieved. I end by briefly speculating that empathy, so conceived, may also play a distinctive social role, enabling what I term ‘transparent fellow-feeling’.