Dorothea is an exceptional woman: she is smart, pious, and beautiful, and the governing principle of her character is her desire to help the needy, seen in her interest in redesigning the local farmers’ cottages. By giving money to Lydgate’s hospital, she is able to help the less fortunate, and by giving money directly Lydgate, she frees him from his debt to Bulstrode. Her philanthropic impulse indicates her essential goodness.
Dorothea is also stubborn and strong-willed, going against common advice to wed Casaubon, a much older man. Her marriage to him is driven by her desire to be taught by him, and she devotes herself to him entirely—and is appropriately devastated when he dies. Unfortunately, Casaubon doesn’t trust her unmitigated devotion, either to his work or in loving him. When Dorothea learns of a clause in his will that forbids her to marry his cousin Will Ladislaw, Dorothea’s devotion to her deceased husband shifts. She feels betrayed by his insinuation that she was unfaithful. In response, Dorothea refuses to finish Casaubon’s work, an indication that she is returning to her independent, pre-marriage self. When Dorothea does marry Ladislaw, she reveals her growth as a person. This marriage is a mutual understanding and partnership, and both members are equals. This marriage required Dorothea to flout convention and forgo her inherited wealth, and her willingness to do so show that she has regained her earlier rebellious energy but with a newfound maturity.