Various authors hold that some emotions (i.e., moral emotions) have the function of orienting people toward ethical actions. In addition to embarrassment, shame and pride, the moral emotion of guilt is believed to affect humans' behavior when they carry out transgressions that violate social and cultural standards. Over the past century, many studies (including controversial ones) have been conducted on guilt. In this study, we analyzed and summarized mainly the most recent literature on this emotion. On one side, the destructiveness of guilt is emphasized. It inflicts punishment and pain on individuals for their errors and can lead to psychopathology (e.g., depression). On the other side, it is described as a ``friendly'' emotion that motivates behavior adapted to social and cultural rules. How can this asymmetry be explained? Different existing views on guilt are presented and discussed, together with recent proposals, supported by research data. Finally, we discussed some systematic models that try to incorporate these different views in a single framework that could facilitate future researches.