When we examine "metaphors for teaching," I think that we are looking at what are the "teachable" moments that emerge out of the literature. Antigone gives us many of those instances. I think that one of the strongest symbols is the title character, herself. Looking at Antigone as a heroine, I think that one great teachable moment is how the line is so very blurred between freedom fighter and terrorist. From Antigone's point of view, her actions are that of a freedom fighter, someone fighting in her own name for her own cause dear to her heart and identity. From Creon's point of view, she is a lawless "terrorist," someone who has no regard for law and someone whose actions are an apparent affront to the word of order. I think that students can use this distinction to analyze how the terms like "terrorist" or "freedom fighter" are subject to bias and personal point of view. It is a great point of view exercise to have students assess both claims about Antigone.
Another issue that presents itself is whether or not one's view of Antigone changes with gender. In other words, if Antigone was a man, how would the play be different? In this, students would probably assess Ismene's role and counsel to her sister. Moreover, it becomes an excellent gender exercise for students to see the role that gender plays in how characters are interpreted and how motives are assessed.
Finally, I think that there is a political or civics discussion present in the belief and faith in convictions. Antigone has a conviction that her brother is going to be honored properly. There is little in way of negotiation in Antigone. She is not going to sacrifice one iota on her stance. I think it might be a good lesson in civics and the ethics of citizenship to talk about if this is healthy or good in a vibrant democracy. Can citizens in a democracy have convictions that must be realized, regardless of cost? What happens when these collide with others' convictions? Is negotiation the only way to ensure civil peace, demonstrating that convictions really have little place in a heterogeneous democracy? Examining these issues in the play and then assessing them with historical examples might make an excellent lesson in civics education.