Compassion (‘suffering with’) is more engaged than simple empathy, and is associated with an active desire to alleviate the suffering of its object. With empathy, I share your emotions; with compassion I not only share your emotions but also elevate them into a universal and transcending experience. Compassion, which builds upon empathy, is one of the main motivators of altruism.
Sympathy (‘fellow feeling’, ‘community of feeling’) is a feeling of care and concern for someone, often someone close, accompanied by a wish to see him better off or happier. Compared to pity, sympathy implies a greater sense of shared similarities together with a more profound personal engagement. However, sympathy, unlike empathy, does not involve a shared perspective or shared emotions, and while the facial expressions of sympathy do convey caring and concern, they do not convey shared distress. Sympathy and empathy often lead to each other, but not always. For instance, it is possible to sympathize with such things as hedgehogs and ladybirds, but not, strictly speaking, to empathize with them. Conversely, psychopaths with absolutely no sympathy for their victims can nonetheless make use of empathy to snare or torture them. Sympathy should also be distinguished from benevolence, which is a much more detached and impartial attitude.