John Proctor is an upright, honest man experiencing a crisis of conscience. He is attempting to fix his marriage and, in doing so, steer clear of the turmoil in Salem. Ultimately, the town's trouble becomes his trouble and Proctor's forthright anger comes into direct conflict with the duplicity and fraud of the Salem witch trials.
Abigail Williams is deceitful and savvy, capable of manipulating almost anyone. She initiates the witch trials successfully in an effort to deflect attention from herself and her friends when they are caught dancing naked in the woods.
Elizabeth Proctor is passive-aggressive (in the modern parlance), pious, and deeply hurt. She cannot trust her husband anymore, though she wants to believe that he remains a good man. Ultimately, she convinces Proctor that she sees him this way, allowing him to finally see himself this way again and then to die with pride.
Revered Parris is a weak and selfish man, striving to secure his tenuous position in Salem through whatever means are available to him, including the witch trials.