To read the shorter Steven Pinker -- one of the many compressed versions of the ideas developed over 800 pages in The Better Angels of Our Nature: Why Violence Has Declined that he has published in newspapers and magazines or offered in interviews -- you might think that the driving force behind the dramatic reduction in violence over the course of human history was an expansion of empathy, the ability to enter into the feelings and sufferings of other. And so it is, to a degree. Pinker attributes the growth of empathy in large part to the development of commerce, which requires interaction, and printing, which helped expand the circle of literacy and, ultimately, the range of human experience that the literate absorb.
But fairly late in his argument, Pinker subordinates empathy to reason as a driver of the "rights revolution" -- the growing expansion of categories of people (and to a degree, now, animals) whom it becomes taboo to subject to violence of various kinds, including second class citizenship. It's reason that expands the circle:
What really has expanded is not so much a circle of empathy as a circle of rights--a commitment that other living things, no matter how distant or dissimilar, be safe from harm and exploitation. Empathy has surely been historically important in setting off epiphanies of concern for members of overlooked groups. But the epiphanies are not enough For empathy to matter, it must goad changes in policies and norms that determine how the people in those groups are treated...abstract moral argumentation is also necessary to overcome the built-in strictures on empathy. The ultimate goal should be policies and norms that become second nature and render empathy unnecessary. Empathy, like love, is in fact not all you need (Location 13,110)."Empathy, like love..." But empathy is not love, not as theologians and moral philosophers -- for example, Martin Luther King -- have defined the latter. Love is bigger than empathy. In King's formulation, it encompasses something like the reason that Pinker places higher on the (social) evolutionary scale.