As one can see, in Acts I and II of Arthur Miller's "The Crucible", all characters have a dark side, replete with moral weaknesses. These personal faults are manifested in the character's actions and in the intricacies of his inner conflict.
John Proctor is a man with many moral weaknesses, the first of which are revealed to the reader in Act I. His most glaring moral fault is his having committed an act of adultery with young Abigail Williams. As soon as he sees her, his face betrays a faint smile. This is evidence that Abigail still has an affect on his behaviour. He also freely admits that he "thinks softly of her from time to time." Obviously he still has not put her out of his mind. He knows what he has done is wrong, yet he cannot, or will not, purge himself of the lustful desires that led him to sin in the first place.
This idea is reinforced by his looking up at Abigail's window, "burning in his loneliness", as Abigail describes it. In many respects John Proctor is also deceiving himself into thinking he is beyond moral reproach. He insists that he and Abigail never touched, yet they surely did, in both the physical and emotional sense. He also reveals something of his strained relations with his wife when Abigail calls her a cold and sniveling woman he does not defend her but merely says, "Do you look for wippin'?" In short, Act I reveals John Proctor's lustful desires and his inability to erase them from his mind.
In Act II we learn more of the effects John's immorality has on his wife, Elizabeth and his sense of justice. As John enters the house he asks Elizabeth to bring in some flowers saying, "It's...