Compassion (from Latin: "co-suffering") is a virtue —one in which the emotional capacities of empathy and sympathy (for the suffering of others) are regarded as a part of love itself, and a cornerstone of greater social interconnectedness and humanism —foundational to the highest principles in philosophy, society, and personhood.
There is an aspect of compassion which regards a quantitative dimension, such that individual's compassion is often given a property of "depth," "vigour," or "passion." More vigorous than empathy, the feeling commonly gives rise to an active desire to alleviate another's suffering. It is often, though not inevitably, the key component in what manifests in the social context as altruism. In ethical terms, the various expressions down the ages of the so-called Golden Rule embody by implication the principle of compassion: Do to others what you would have them do to you.