Initially, Proctor is portrayed as a flawed and somewhat arrogant individual. He harbors a secret affair with Abigail Williams, a young woman who later accuses several innocent people of witchcraft, including Proctor's wife, Elizabeth. Proctor is initially hesitant to confront Abigail's lies and preserve the reputation of his family and community.
However, as the play progresses, Proctor's moral compass begins to shift. He becomes increasingly troubled by the injustice and hysteria that have gripped Salem. He realizes that his silence and inaction have contributed to the escalating crisis.
A pivotal moment in Proctor's journey occurs during his examination in court. He decides to reveal the truth about his affair with Abigail, hoping to expose her deceit and end the witch trials. This decision demonstrates his growing sense of moral responsibility and willingness to sacrifice his reputation for the sake of justice.
As the play reaches its climax, Proctor's self-awareness deepens further. He confronts his past mistakes and accepts his role in the unfolding tragedy. He understands that his initial choice to engage in the affair with Abigail has contributed to the web of lies and manipulation that has ensnared the community.
In his final moments, John Proctor displays unwavering integrity and courage. Despite the overwhelming odds stacked against him, he chooses to stand up for what is right and refuses to falsely confess to witchcraft. His defiance against the corrupt court and his willingness to face the consequences of his actions illustrate his profound moral transformation.
Thus, throughout the course of the play, John Proctor learns about his capacity for deceit and moral weakness, but he also discovers his inner strength, sense of justice, and capability for redemption.