What is a morally mature adult? On the face of it, this is a straightforward question, which suggests that there is an equally straightforward reply. We have already seen, however, that the word ‘mature’ is an evaluative word which can be defined in a number of different ways. A person may be described as mature if he has learned, and follows, the rules relating to any particular group of which he is a member or participant – at home, or school, at college, or work, in a club, or local community, in a country or even simply as a member of the human race. A person may be described as mature who has learned the meaning and value of discipline and observes this in his behaviour; it will be evinced not only in groups which ‘specialise’ in discipline, such as the army, the police force, or the Church, but in the smaller everyday matters of being punctual, telling the truth, keeping promises, and not cheating. These are all outward signs of what most people would describe as mature behaviour; the question is whether there is not more to moral maturity than this.