Diction encompasses the choice of words that defines the writing style of an author, or a speaker. It is a determinant factor in what would be considered good writing, or a good speech, because the choice of words will convey the appropriate meaning, tone, and emotion that the author aims to send out.
Chapter 1 of The Scarlet Letter, "The Prison Door" has, as its main focus, the description of said prison as a piece of history that evokes pain and nostalgia. The main reason for these emotions is the presence of a rose bush which, with resilience, has decided to remain there decorating the ugly door with its rich colors.
This being said, the main focus here is the use of diction to describe the prison, juxtapose its description to that of the bush, and bring out the meaning of both symbols within the context of the chapter.
When describing the prison, Hawthorne describes it as "ugly" in both the aesthetic as well as the spiritual meaning.
Before this ugly edifice, and between it and the wheel-track of the street, was a grass-plot, much overgrown with burdock, pig-weed, apple-pern, and such unsightly vegetation, which evidently found something congenial in the soil that had so early borne the black flower of civilized society, a prison.
Notice the choice of verbiage to extrapolate the ugliness of the place. Of all overgrowing vegetation Hawthorne picks the ugliest sounding ones, as well. Moreover, all of these elements came together agreeably to create "the black flower of civilization". The metaphor of black flower stems from the fact that the prison houses equally dark and lonely souls.
Contrastingly, the rose bush is there, perhaps as a token to the memory of the brave Anne Hutchinson, whom Hawthorne admired for her courage. Perhaps it was there merely to make the prisoners smile. Yet, just like the description of the prison evokes negativity, the description of the rose bush evokes a glint of hope for the future of our civilization.
It may serve, let us hope, to symbolize some sweet moral blossom that may be found along the track, or relieve the darkening close of a tale of human frailty and sorrow