Arthur Dimmesdale is a very enigmatic character. His public behavior contrasts dramatically with his private practices, his philosophy of conduct and propriety are contradictory, and the overall image of himself that he intends to create to his followers leaves room for speculation: is Dimmesdale insane? Is he a wolf disguised as a lamb? Is he egotistical and merely seeks attention? Is he aware of his bizarre and awkward actions?
In order to properly answer the question, it is best to go back and explore in-depth the extent to which Dimmesdale's personality renders him rebellious without a cause, and yet subservient without a clear reason. It is clear, however, that whatever maxims support his thoughts processes, they all lead to punishment, self-torture, and isolation.
The self-imposed isolation of Arthur Dimmesdale consists on bouts of self-flagellation, followed apparently by a number of scary and dangerous forms of self-punishment, all aiming to redeem him from the wrath of God. However, the effects of his isolation make him all the more enigmatic. The members of the congregation are so fixated on Dimmesdale, and so willing to make of him a saint of clay, that even when it is obvious that the man must be doing something disturbing during his off-duty hours, they still see his clear guilt and pain as some sign of providence and sainthood.
Chapter III explains this quality of Dimmesdale even further
as of a being who felt himself quite astray and at a loss in the pathway of human existence, and could only be at ease in some seclusion of his own.
This proves, beyond any doubt, that Dimmesdale's isolation, though a product of his own sin, has an ironic reaction of admiration among his somewhat ignorant followers.
It is known of Arthur Dimmesdale is that he is young, educated, and seems to posess a charisma that allows him to envelop the trust and attention of everybody. Yet Hawthorne specifically gives Dimmesdale the looks and demeanor of a demi-god.
he trode in the shadowy by-paths, and thus kept himself simple and childlike; coming forth, when occasion was, with a freshness, and fragrance, and dewy purity of thought, which, as many people said, affected them like the speech of an angel.
This is interesting because Dimmesdale's actions are completely juxtaposed to his looks. After all, he lies to his followers by covering his sin, he abandons Hester by not taking her side, nor does he take care of his own daughter, Pearl. Moreover, even at the end of the novel, when Dimmesdale makes the decision to confess, he jilts Hester once again.
Therefore, it is likely that Dimmesdale is a psychological hermit, so to speak; his isolation is both psychological and physical. He is a laudable member of the community and a solid leader. Still, he is weaker, more cowardly, and less apt to lead and advice than any of the people who follow him and admire him.