One of the most influential Hawthorne biographers is Terrence Martin, who wrote Hawthorne in 1965. Other notable biographies include Nathaniel by Harold Bloom, and Nathaniel Hawthorne in His Times by James R. Mellow. The latter is available on eNotes as a study guide.
All biographers agree that Hawthorne had a time period that is known as his "solitary years." These took place between 1825 and 1837 upon his return from Bowdoin College (Brunswick, ME) to his mother's home in Salem, Massachusetts. According to Hawthorne himself, he spent a good deal of time in what he thought to be a haunted bedroom. In it, he sketched and wrote a lot of work, which he eventually discarded as drafts.
All this said, we know as readers that Hawthorne was a man of a moderately eccentric nature (Gupta 1972, "Hawthorne's Treatment of the Artist.") who felt that solitude was necessary to test himself and learn how to master his craft. However, according to Nathaniel Hawthorne in His Times, he was not an over-the-top eccentric. In fact, he was able to find love and give up that lonely period thanks to his neighbor, Sophia Peabody, whom he later married.
Nevertheless, we see loneliness as the key ingredient in the lives of many of his characters. In The Scarlet Letter we find that each major character is destined to a life of solitude, whether physical, mental, or spiritual.
- Hester, isolated from the rest of the village as an adulterer, is sent to live in the outskirts of the settlement on her own.
- Dimmesdale, haunted by guilt, also decides to live a life of solitude trying to atone for what he did.
- Chillingworth, who was presumed dead, enters the settlement alone and decides to attach himself to Dimmesdale, living with him as his physician while secretly plotting to exert the truth of his relationship with Hester. Nevertheless, his soul is in constant, isolated torment.
- Pearl, the only daughter of Hester, cannot blend in with other children and lives with Hester, also isolated from the rest of the villagers as the daughter of the adulteress.
In "The Minister's Black Veil" we find Rev. Hooper isolating himself from his parishioners by wearing a scary black veil that covered his face.
In "Young Goodman Brown" we find the topic of isolation and alienation when Goodman Brown leaves his wife and embarks on a night journey where he presumably meets the devil and is forever marked to live in isolation upon his return.
Therefore, both in literature and in his life, Hawthorne sees alienation and isolation as a conduit for understanding, or discovering, who we are and what we are capable of doing.