  Socrates employs this general strategy four times. In Book Four, he twice considers conflicting attitudes about what to do. First, he imagines a desire to drink being opposed by a calculated consideration that it would be good not to drink (439a–d). (We might think, anachronistically, of someone about to undergo surgery.) This is supposed to establish a distinction between appetite and reason.  Then he considers cases like that of Leontius, who became angry with himself for desiring to ogle corpses (439e–440b). These cases are supposed to establish a distinction between appetite and spirit. In Book Ten, Socrates appeals to the principle of non-opposition when considering the decent man who has recently lost a son and is conflicted about grieving (603e–604b) (cf. Austin 2016) and when considering conflicting attitudes about how things appear to be (602c–603b) (cf. Moss 2008 and Singpurwalla 2011). These show a broad division between reason and an inferior part of the soul (Ganson 2009); it is compatible with a further distinction between two inferior parts, spirit and appetite.