Roger Chillingworth, Hester’s former husband, is more pitiable than Dimmesdale because he appears to have led a loveless life, as the name Chillingworth implies. He cuts an unassuming figure, being small and something of a hunchback, but his intellectual abilities far outshine his physical shortcomings:
There was a remarkable intelligence in his features, as of a person who had so cultivated his mental part that it could not fail to mould the physical to itself, and become manifest by unmistakable tokens. (Chapter 3)
Chillingworth is isolated from society, devoting himself to scholarly and medical pursuits, but although he seems incapable of forging close human relationships he does apparently try to do his best by his young wife initially. When Hester plays him false, however, all the bitterness in his nature comes to the fore. Ultimately, his more positive qualities go to waste as he allows himself to become consumed by the need for vengeance.
This unhappy man had made the very principle of his life to consist in the pursuit and systematic exercise of revenge. (Chapter 24)
Dimmesdale suffers prolonged agonies of conscience after committing adultery and is worn down by his guilt, but he loves and is loved. Chillingworth by contrast seems to have no close relationships at all, and lives and dies an embittered figure, an ‘unhumanized mortal’ bent upon his ‘devil’s work’ (Chapter 24).