Why is Thomas Putnam such a bitter man in The Crucible?

Thomas Putnam is bitter for two reasons that come together in the accusations surrounding the trial. First, he feels he's been done wrong—that neighbors and community members have taken advantage of him over the years. This makes him ready to lash out. Second, he's ambitious, specifically materially ambitious. He wants to be a rich landowner. Well, both the way people have done him wrong and the general focus of the community get in the way of this. So, both his nature and his context contribute.