Dorothea Brooke is the protagonist of Middlemarch. She stands out from the other characters due to her sincere good intentions. As an intelligent, religious, and forward-thinking young woman, her main desire in life is to help other people. When the novel begins, she is satisfying this desire by trying to redesign many of the local cottages. These cottages are rented by the working-class people who live on the large estates owned by her uncle and his middle-class peers. Improving these cottages has no direct benefit to Dorothea but she pursues the project nevertheless. Later, she funds Lydgate's hospital and searches for local charitable causes which would benefit from the money which she does not want or need. This philanthropy stands in stark contrast to most of the characters in Middlemarch. While most other characters have an ulterior motive for their good deeds, Dorothea is genuine in her desire to help people. Her actions speak to her sincerity, as does her modesty and refusal to boast about her good deeds.

For all her good qualities, however, Dorothea is not without her flaws. Her desire to change the world brings about the biggest mistake in her life, one which compounds further and further until it leaves her in a miserable state: her marriage to Casaubon.