At one point, John Proctor identifies revenge as the true evil that is affliciting Salem Village. What evidence is there to support Proctor's claim?

The primary support for John's claim is the incident of
the poppet found in the Proctors' household. The little doll belongs to Elizabeth, and
when questioned, she does not hesitate to claim it because she is innocent of any
wrongdoing. However, a needle is found in the poppet, evidence to those in the drama
that Elizabeth had been practicing witchcraft, stabbing the poppet to cause pain for
someone she wished to harm.

Elizabeth, however, had not
pushed the needle into the poppet; Abigail Williams had done it to incriminate
Elizabeth, to see that she is condemned and executed. Abigail hates Elizabeth and wants
John Proctor for herself, even though he ended their affair. John knows this, and Mary
Warren, when she is telling the truth, confirms that Abigail is misleading the court.
John tells the court that vengeance is afoot in Salem, but his protests are
ignored.