With pity, you see someone suffering and you feel sorry for him or her, but at the same time a part of you is glad that person isn’t you. Your mind is busy thinking of reasons you wouldn’t make the mistakes he or she made that led to the suffering. Pity involves both a protective distancing and a measure of condescension. Your sorrow for the sufferer comes from a place of separateness.
When you feel empathy, you see a person suffering, and because you have a certain level of self-awareness, you know a part of you suffers in the same way, so you identify with the sufferer’s pain. At some level, that person is the same as you. Empathy opens your heart and produces a strong desire to help the person. The danger with empathy, however, is that if you identify too much, you will feel a pressure to relieve the other’s misery. You can’t tolerate your own pain, so you can’t stand for the other to spend any time suffering. The other common consequence of having too much empathy is to distance from the other person because his or her pain makes you hurt too much.
When you feel compassion, you see a person suffering, you feel empathy for him or her, and you know that the other has a Self which, once released, can relieve his or her own misery. If people relieve their own suffering, they learn to trust their own Self, and they learn whatever lessons the suffering has to teach them. Compassion, then, leads to doing whatever possible to foster the release of the other’s Self rather than become the other’s healer. With compassion, you can be open-heartedly present with sufferers without feeling the urge to change them or distance from them. This kind of Self-presence will often release their own Self. "
In Schwartz, R. (2001). Introduction to the Internal Family Systems Model