The character of Arthur Dimmesdale is a fascinating character to study in this novel, as he ironically finds that his secret guilt through his illicit sexual relationship with Hester and fatherhood of Pearl actually makes him more popular and effective as a priest, as the guilt that it inspires within him gives him the ability to empathise and connect with those around him. This is something that his parishioners respect and respond to with open arms. However, one aspect that presents Arthur Dimmesdale as a tragic hero is the way that he is unable to express his guilt and sin and therefore internalises it. Note the following conversation he has with Hester towards the end of the book:
Happy are you, Hester, that wear the scarlet letter openly upon your bosom! Mine burns in secret! Thou little knowest what a relief it is, after the torment of a seven years' cheat, to look into an eye that recognises me for what I am!
Dimmesdale therefore internalises his unexpressed and secret guilt and sin, symbolically wearing his own scarlet letter on his breast as a representation of that pent up sin. Tragic it is indeed that he finds no way of expressing that guilt and sin publicly like Hester has, for even after he does admit his sin on Election Day, the majority of his listeners do not believe him and, through his death, he becomes an icon of saintliness and holiness. This is tragic given that all Arthur Dimmesdale wanted in his life was to be punished and treated similarly to Hester.