Chapter 4 outlines the debates of wether there is a separate category of supererogatory actions within the categorical system of the deontic logic. Deontologigal Antisupererogationism doubts that such a category can exist using the argument that morally valuable actions are to be assigned to the category of duty due to their moral value (see Sect. 4.1). Deontological Supererogationism describes the category of supererogatory actions as a subclass of the imperfect duties (see Sect. 4.2) or as recommended actions (see Sect. 4.3) or as actions whose omission is permitted (see Sect.4.4) or as voluntary actions (see Sect. 4.5) or as praiseworthy actions (see sect. 4.6).