Violence against women
One of the purposes of this novel seems to be that Joyce Carol Oates wants the reader to have to empathize with rape victims. She does this skillfully by showing the poor reaction of Marianne's father. Instead of letting her be the authority on her own emotions, he immediately seizes control and demands that she rush through difficult decisions. Marianne is rejected by her own father when she needed him most. This is a revealing description of what many rape victims endure, ostracized by their loved ones when they needed them most.
The complicated aftermath of injustice
When evil is done against an innocent victim, that person's psychology is often shattered by the trauma. This leaves them ill-prepared to deal with the aftermath. For instance, rape victims like Marianne often choose not to press charges, because they know how humiliating and painful the legal process would be. Marianne has to balance her emotional disarray with problems so complicated, even her father spirals into mental unhealth. His alcoholism is a symbol of the chaos that even one act of violence can cause.
The difficulty of justice
What does justice look like for Marianne? Is it wrong for her brother to murder Marianne's rapist in cold blood? Or is such divine recompense necessary? (Divine recompense, because Marianne's brother decides the fate of another person). The effect of such questions helps to complement Marianne's difficult, complicated decision to keep the trauma private. To pursue justice in a court would have involved Marianne making the allegations public, and she feels that in her adolescent state, she would not be successful. Therefore, justice is something she can't pursue for herself. Obviously, the issue of justice is way more complicated for Marianne than just calling the cops and sending the bad guy to jail.
