Compassion, sympathy, empathy, and pity are not mainstream themes in the history of philosophy, but have been taken up frequently by philosophers. Starting with the ancient Greek philosopher Aristotle, Spinoza, Descartes, Hume, Adam Smith, Schopenhauer, and many others have discussed the concept of compassion. More recently, Jacques Derrida and Martha C. Nussbaum, among others, have contemplated it. In reviewing their patterns of thought, one can see that the shift in the concept of compassion is the transition of the answers to the questions "How do we feel compassion for other(s)?" and "Who is/are the other(s) who deserve compassion?” This study explores the development of "sympathetic imagination" in philosophy, how the subject of compassion has expanded, and where the source of compassion is found.