What excuse does Miller give for John's affair with Abigail?
In Act 4, Miller gives somewhat of an excuse for John's behavior. It is more of an acceptance of shared responsibility by Elizabeth, John's wife.
In an effort to get John to perjure himself and admit to witchcraft, Danforth and Parris decide that Elizabeth should speak with John. When John explains to Elizabeth that he is considering telling the courts he engaged in witchcraft, she tells him that she knows he is a good man. She tells him that she has her own sins to count for. She says, "It needs a cold wife to prompt lechery," meaning that she takes partial blame. She says, "I counted myself so plain, so poorly made, no honest love could come to me! Suspicion kissed you when I did; I never knew how I should say my love. It were a cold house I kept!"
This is somewhat of an excuse because Elizabeth is saying that she was not the wife she should have been. She realizes that because she was withdrawn from John, he sought intimacy elsewhere. This statement is Elizabeth’s way of forgiving John.