An imaginary circle of empathy is drawn by each person. It circumscribes the person at some distance, and corresponds to those things in the world that deserve empathy. I like the term empathy because it has spiritual overtones. A term like sympathy or allegiance might be more precise, but I want the chosen term to be slightly mystical, to suggest that we might not be able to fully understand what goes on between us and others, that we should leave open the possibility that the relationship can't be represented in a digital database.If someone falls within your circle of empathy, you wouldn't want to see him or her killed. Something that is clearly outside the circle is fair game. For instance, most people would place all other people within the circle, but most of us are willing to see bacteria killed when we brush our teeth, and certainly don't worry when we see an inanimate rock tossed aside to keep a trail clear.The tricky part is that some entities reside close to the edge of the circle. The deepest controversies often involve whether something or someone should lie just inside or just outside the circle. For instance, the idea of slavery depends on the placement of the slave outside the circle, to make some people nonhuman. Widening the circle to include all people and end slavery has been one of the epic strands of the human story - and it isn't quite over yet.A great many other controversies fit well in the model. The fight over abortion asks whether a fetus or embryo should be in the circle or not, and the animal rights debate asks the same about animals.When you change the contents of your circle, you change your conception of yourself. The center of the circle shifts as its perimeter is changed. The liberal impulse is to expand the circle, while conservatives tend to want to restrain or even contract the circle. Empathy Inflation and Metaphysical AmbiguityAre there any legitimate reasons not to expand the circle as much as possible?There are. To expand the circle indefinitely can lead to oppression, because the rights of potential entities (as perceived by only some people) can conflict with the rights of indisputably real people. An obvious example of this is found in the abortion debate. If outlawing abortions did not involve commandeering control of the bodies of other people (pregnant women, in this case), then there wouldn't be much controversy. We would find an easy accommodation.Empathy inflation can also lead to the lesser, but still substantial, evils of incompetence, trivialization, dishonesty, and narcissism. You cannot live, for example, without killing bacteria. Wouldn't you be projecting your own fantasies on single-cell organisms that would be indifferent to them at best? Doesn't it really become about you instead of the cause at that point?