Compassion was the quality of an individual or species. It was characterized by having pity, sympathy, and concern for the misfortune and suffering of an individual. Although having this quality did not imply there was an understanding of the situation, an individual could be motived to helping the other person.
In 2265, Captain James T. Kirk felt compassion for his friend Gary Mitchell, who was being mutated by psionic energy into a new kind of Human. Kirk's compassion delayed his response to Gary, allowing him to grow stronger. Gary told Kirk he should have killed him sooner, and joked that "Compassion and command are a fool's errand." Later, when confronting the mutated Elizabeth Dehner, Kirk said that what a god needed above all else was compassion. (TOS: "Where No Man Has Gone Before")