It is because his pain needs to be compared to Hester's. His choice must have its alternative. The reader must see what could have happened if Dimmesdale had chosen another path, chosen the second option, or vice versa. Nathaniel Hawthorne intertwines the two characters perfectly. Arthur Dimmesdale, a perfect religious priest who the people of the community believe to be an angel sent to guide them to the promised land and Hester Prynne, the young woman of the community who slept with someone other than her husband and is despised by every person and even from heaven itself. Every character needs its opposite. Arthur and Hester are not the good guys and Roger Chillingworth is not their opposite. Roger is just a character necessary to move the story forward; a character needed to bring opposites together into one. The story moves around him and Hester. No one wants to read a story about a girl who gets pregnant, they want to read one where her lover gets into as much trouble as she does