* He has grown fond of her. Despite their frequent disagreements, Higgins has developed a genuine affection for Eliza. He admires her intelligence, her strength of character, and her determination to improve herself. He also enjoys her company, and he finds her to be a stimulating conversationalist.
* He needs her for his experiment. Higgins is determined to prove that he can transform a lower-class woman into a lady, and Eliza is the perfect subject for his experiment. He believes that if he can teach Eliza to speak proper English and adopt the manners of high society, then he will have proven his point.
* He feels guilty about the way he has treated her. Higgins knows that he has not always been kind to Eliza, and he feels guilty about some of the things he has said and done to her. He wants to make amends, and he hopes that Eliza will forgive him if she comes back to Wimpole Street.
In the end, Eliza does decide to return to Wimpole Street, and she and Higgins continue to work together on his experiment. Despite the challenges they face, they eventually achieve their goal, and Eliza is transformed into a lady.
