How does Pip persuade Jaggers to give him more information about Estella when he first refuses?

Pip cannot convince Jaggers to divulge any information, however, until he appeals to Wemmick’s human, kind side, the side that until now Wemmick has never shown in the office. Jaggers is so surprised and pleased to learn that Wemmick has a pleasant side that he confirms that Estella is Molly’s daughter, though he didn’t know Magwitch’s role in the story.