I believe that many people misunderstand what empathy really is. I would argue that empathy is an emotional response to the (perceived) emotions of other sentient beings. I believe that empathy is a form of love and to empathize with someone is to identify with their emotional state of mind (ie. you are happy because they are happy, and sad because they are sad). Imagination is the basis of empathy since we cannot literally feel what other people feel. If empathizing with someone means that you identify with their emotional state of mind then you have a vested interest in whoever you empathize with feeling happy and not feeling sad. Basing ethical decisions on empathy alone would naturally lead to hedonism : the idea that happiness is the *only* intrinsic good and suffering is the *only* intrinsic bad, since, if we based our decisions on empathy alone, our only concern would be how other people felt.
Although we intuitively feel that we desire things other than pleasure, this is an illusion, since pleasure is actually the satisfaction of desire. We're hardwired to associate the objects of our emotions with our emotions but it's pleasure/stress that we value/disvalue, not the things that cause pleasure/stress. If we adopted an ethics of empathy/hedonism, we could only regard an action as morally right if it minimized/prevented stress or increased happiness, wrong if it caused stress or frustrated someone's desire to be happy and neutral if it did neither. This has some uncomfortable conclusions for most people (for example, an empathy oriented/hedonist world view would justify infidelity or lying if neither had any negative consequences) but I haven't yet heard a good argument against hedonism or for the idea that things other than suffering/happiness actually matter.
Although we intuitively feel that we desire things other than pleasure, this is an illusion, since pleasure is actually the satisfaction of desire. We're hardwired to associate the objects of our emotions with our emotions but it's pleasure/stress that we value/disvalue, not the things that cause pleasure/stress. If we adopted an ethics of empathy/hedonism, we could only regard an action as morally right if it minimized/prevented stress or increased happiness, wrong if it caused stress or frustrated someone's desire to be happy and neutral if it did neither. This has some uncomfortable conclusions for most people (for example, an empathy oriented/hedonist world view would justify infidelity or lying if neither had any negative consequences) but I haven't yet heard a good argument against hedonism or for the idea that things other than suffering/happiness actually matter.