Hume’s principle of sympathy is a foundational element of his ethical system, playing a critical role in moral judgment. In contemporary society, sympathy continues to exert a significant influence on social and ethical life. However, the issues arising from the misuse of sympathy warrant serious attention. Over time, the boundaries between Hume’s concept of sympathy and related notions such as pity and empathy have blurred, leading to confusion and even the gradual replacement of these terms. This paper seeks to clarify the distinction between Hume’s original concept of sympathy and these modern interpretations, thereby tracing the evolutionary process of sympathy. By examining instances of moral thinking, moral stance, and moral judgment abuses—each resulting from the erosion of reason and self-love in concepts like pity and empathy—it becomes clear that these distortions have profound consequences. Restoring the true concept of sympathy is not only essential for revitalizing morality but also for ensuring the achievement of justice. In this corrective process, the rationality of the observer is paramount, and this rationality can be cultivated through the construction of group morality.