In The Scarlet Letter, what is Chillingworth's most serious sin?

's most
horrible sin is this: In seeking revenge, he sets out to deliberately and methodically destroy
another human being, . When Chillingworth comes into the settlement to find his wife standing on
the scaffold with another man's baby in her arms, his shock turns quickly into a lust for
retribution. When he meets within the jail after she is taken down from the scaffold, he
extracts from her the promise that she will not reveal his identity. His intent is clear;
protected by the veil of anonymity, he intends to discover and pursue Hester's partner in sin.
Hester's husband's plan for revenge has already formed in his mind, and he takes up his new
false name, Chillingworth.

Living in the village as the physician he is,
Chillingworth waits and watches, obsessed with determining which man fathered . Once he suspects
the minister, he moves in with Dimmesdale, pretending to be his caring physician. Chillingworth
uses his position to probe Arthur's conscious and subconscious mind, tormenting him
psychologically, and perhaps, it is implied, poisoning him physically. When Chillingworth
discovers the "proof" he has sought (something shocking appearing on Arthur's chest--a
second scarlet letter?), he dissolves into a state of complete moral corruption, overcome with
joy at the pain and suffering of another. Chillingworth has not only betrayed his morality as a
human being, he has corrupted his profession, using his skills as a physician to destroy rather
than heal.

Until the novel's dramatic conclusion, Chillingworth uses all his
power to keep Arthur from making a public confession. So long as Arthur hides his secret sin, he
remains trapped in Chillingworth's devious daily torture. When Arthur finally does confess,
standing on the scaffold with both Hester and Pearl, he frees himself from the physician's grip,
as Chillingworth acknowledges:

"Hadst thou sought the
whole earth over, said he, looking darkly at theclergyman, there was no one place so secret,no
high place nor lowly place,where thou couldst have escaped me,save on this very
scaffold!"

The greatof Roger Chillingworth's
revenge, however, is that Dimmesdale grows in spiritual insight and achieves peace, whereas
Chillingworth wastes his own life, destroys his own integrity, corrupts his own soul, and spends
what's left of his life trying to make up for his most terrible sin.