Sibling Rivalry
Antigone and Ismene are the polar opposite of each other. Ismene is said to be "reasonable" (all implication being that Antigone is not) and she is a well-mannered, obliging and obedient girl with a full figure and pleasing personality. Antigone is a woman before her time, reluctant to the point of obstinacy to fitting in and becoming like all the other girls; she is skinny and sallow in coloring and is obstreperous and argumentative. In many ways the women fall into the "good girl versus bad girl" theme and this is true in both appearance and personality. Their rivalry is also in their willingness or otherwise to conform to what it is to be feminine. Curvy, girly Ismene relishes her femininity whereas Antigone seems to hate it. This dislike of everything feminine can be attributed to their rivalry when it comes to suitors, and Antigone's jealousy of Ismene's attractiveness and the way in which she appeals to men. She therefore steals Ismene's make up pretty dresses to try to make herself appear more like her sister and capture Haemon's heart. This is an important theme because it shows us that despite Antigone's vicarious womanhood through Ismene, this kind of love is not destined for her.
Society's View of Femininity
Society's view of femininity at the time of the play is very one-dimensional and the job of a woman seems to be to appear the living embodiment of a woman created in art; they are to be beautiful, curvy and immaculately dressed and made-up but must not be argumentative, obstinate or have any desire to think for themselves. In short, to be feminine at this time is to fit the mould created without questioning it in any way at all. Antigone does not fit this mould at all and so the theme relates to her in that it highlights her "un-feminine" physicality and the lack of femininity in her personality. Ismene fits the mould perfectly and is apparently happy to do so. The theme of femininity shows the nature of the difficulty of the sisters' relationship with each other and is really at the root of their rivalry.
Tragedy
The play explains that tragedy exists as a mechanism in its own right and is not affected by anything that humans think or do. Humans are therefore unable to change it because it has been pre-destined and the wheels of the tragedy are in motion outside of human control. This throws up an interesting dynamic in that if it is already set in motion the behavior of the characters is therefore unimportant in the scheme of things. Rather than a set of circumstances waiting to happen, a tragedy is a series of events already written like the lines of a play, and humans can merely read their lines, but cannot change them. Tragedy is not melodramatic (or dramatic at all) because is a set of circumstances rather than a set of actions or emotions.
