 In Letter 120, Seneca explains how we arrive at the notion of the good. This question is a much-discussed topic in Stoic ethics. The Stoics hold that, in the process of growing up, human beings acquire rationality, which importantly consists in acquiring preconceptions (prolêpseis). Once a human being has reason in this minimal sense, she can improve and eventually perfect her rationality. As part of this process she comes to acquire the concept of the good. The transitional moment in which a human being finally and fully recognizes that only virtue (consistency) is good is momentous: this is the moment in which a fool becomes a wise person (Cicero, De fin. 3.20–22). At that point, a human being acquires what we might call the scientific concept of the good. She now masters a concept of the good that gets things right—once one has this concept, one is not going to fall back on misguided ideas such as ‘money brings happiness’. But does it not seem that we have a notion of the good before, eventually, turning into wise people, if we do? We here must distinguish two notions. First, human beings have a preconception of the good—we call things good before understanding any of the truths of Stoic philosophy. But second, we might, as progressors, also come to see the point of the Stoic claim that only virtue is good, without yet being fully able to consistently appreciate its truth in our lives. As we have seen, it is this condition of the progressor that Seneca has in mind as the objective he hopes to achieve in many of his writings.