Compassion unites people during times of suffering and distress. Unfortunately, compassion cannot take away suffering. Why then, is compassion important for people who suffer? Nurses work in a domain where human suffering is evidently present. In order to give meaning to compassion in the domain of professional care, it is necessary to describe what compassion is. The purpose of this paper is to explore questions and contradictions in the debate on compassion related to nursing care. The paper reviews classical philosophers as well as contemporary scientists' main arguments on compassion. First, I will examine the relationship between compassion and suffering. Second, how does one recognize serious suffering? This issue raises questions about the role of imagination and the need for identification. Third, literature describes compassion as an emotion. Some philosophers consider emotions uncontrollable feelings; others see a clear rational dimension in emotions. In order to determine what compassion is, it is necessary to weigh these contradictional arguments. Fourth, I will discuss motives for compassion. Is compassion an act of altruism or egoism? In this debate Nietzsche and Schopenhauer are well-known opponents. Today, analysis of their arguments leads to some surprising conclusions. Fifth, there is the issue of fault and compassion. Can we only feel compassionate when people who suffer are not to blame for their own suffering? Such a condition faces professional caretakers with a dilemma which needs a thorough analysis if compassion is to be of use in the field of professional care. Finally, I will explore the moral meaning of compassion. Compassion, described as a concept with cognitive as well as affective dimensions, also has volitional and behavioural aspects. These aspects specifically are of importance to nursing care and further research of compassion in the nursing domain.