Explain this statement from The Scarlet Letter: "He [Chillingworth] became, thenceforth, not a spectator only, but a chief actor, in the poor minister's interior world."From chapter 11
This means that Chillingworth, having satisfied himself that Dimmesdale the minister is Hester's secret lover, now starts to actively torment him, under the guise of helping him as his personal physician. Dimmesdale, too wrapped up in his own troubled thoughts over his guilt, does not actually suspect Chillingworth's real identity as Hester's wronged husband, but he comes to fear him more and more. Chillingworth is always there, always haunting him. It might be said that Chillingworth comes to function as the external symbol of Dimmesdale's inner guilt. Chillingworth aims to eventually worry a confession out of Dimmesdale, and Dimmesdale does finally admit to his adultery, but on his own terms and of his own free will, alongside Hester and Pearl. So Chillingsworth feels cheated at the end.