In recent decades, a large body of work has highlighted the importance of emotional processes in moral cognition. Since then, a heterogeneous bundle of emotions as varied as anger, guilt, shame, contempt, empathy, gratitude, and disgust have been proposed to play an essential role in moral psychology. However, the inclusion of these emotions in the moral domain often lacks a clear functional rationale, generating conflations between merely social and properly moral emotions. Here, we build on (i) evolutionary theories of morality as an adaptation for attracting others’ cooperative investments, and on (ii) specifications of the distinctive form and content of moral cognitive representations. On this basis, we argue that only indignation (“moral anger”) and guilt can be rigorously characterized as moral emotions, operating on distinctively moral representations. Indignation functions to reclaim benefits to which one is morally entitled, without exceeding the limits of justice. Guilt functions to motivate individuals to compensate their violations of moral contracts. By contrast, other proposed moral emotions (e.g. empathy, shame, disgust) appear only superficially associated with moral cognitive contents and adaptive challenges. Shame doesn’t track, by design, the respect of moral obligations, but rather social valuation, the two being not necessarily aligned. Empathy functions to motivate prosocial behavior between interdependent individuals, independently of, and sometimes even in contradiction with the prescriptions of moral intuitions. While disgust is often hypothesized to have acquired a moral role beyond its pathogen-avoidance function, we argue that both evolutionary rationales and psychological evidence for this claim remain inconclusive for now.