Chapter 9 of The Scarlet Letter illustrates how Chillingworth uses his scientific background to become a leech that vengefully latches onto and sucks the life out of Dimmesdale. He appears in town

without other introduction than the learning and intelligence of which he possessed more than a common measure. As his studies, at a previous period of his life, had made him extensively acquainted with the medical science of the day, it was as a physician that he presented himself. … He soon manifested his familiarity with the ponderous and imposing machinery of antique physic; in which every remedy contained a multitude of far-fetched and heterogeneous ingredients, as elaborately compounded as if the proposed result had been the Elixir of Life.

This quote intricately describes his background as a cold scholar. First, he has no connection to others. Having sent Hester ahead by herself to Boston, he later arrives without anyone knowing his true identity. He quickly distances himself from his wife and assumes the false (yet apt) name Chillingworth. Erudition and intellect are his most outstanding and only traits that are valued by others; they provide the only means by which he can integrate himself into the town. Also, earlier in their marriage before both he and Hester moved to Boston, Chillingworth cared more about his studies than about his younger wife.

Second, this quote suggests that he is a shapeshifting imposter professionally. Although he familiarized himself “extensively” with “medical science,” he is not necessarily an actual doctor. He is a scientist who presents himself as a physician. He continues this disingenuous self-representation when he poses as Dimmesdale’s personal physician—and causes the minister’s health to worsen, not improve.

Third, this quote emphasizes his obsessive, erudite nature. He possesses “familiarity”—knowledge of and comfort—with scientific concepts that are ordinarily perplexing and intimidating to others. Chillingworth handily concocts complex treatments with “far-fetched and heterogeneous ingredients.” He wields his intellect and skill as if he were a powerful wizard.