In the story of The Crucible John Procter previously held an affair with his old maid before Elizabeth fired her and sent her off. With Abagail (I believe that is her name) getting her friends in on the Witch ruse, you see her specifically target Johns wife so she may be locked up and Abagail can have John for herself. John Proctor is well aware of this and this is why he sees it as more than witchcraft. He also does see it over land and wealth as well.
