What is the name of the person that invites James Hart and his classmates to their cocktail party?
James Hart starts his first year at Harvard Law School in a very bad way. In his contract law course with Professor Charles W. Kingsfield Jr., he assumes the first class will be an outline of the course. When Kingsfield immediately delves into the material using the Socratic method and asks Hart the first question, Hart is totally unprepared and feels so utterly humiliated that, after class, he throws up in the bathroom.
Hart is invited to join a study group with five other students:

Franklin Ford, the fifth generation of Fords at Harvard Law School
Kevin Brooks, a married man with a photographic memory, but no analytical skills
Thomas Anderson
Willis Bell, an abrasive individual who is devoted to property law
O'Connor (Robert Lydiard)While out getting pizza, Hart is asked by a woman, Susan Fields, to walk her home, due to her feeling uncomfortable with a man who had been following her. Hart returns to her house soon after and asks her on a date, after which they begin a relationship. Their relationship is complex; she resents the time he devotes to his studies, while he expects her to provide him with a great deal of attention and wants a firm commitment. When Hart and his classmates are invited to a cocktail party hosted by Kingsfield, he is stunned to discover that Susan is Kingsfield's married daughter. (She is, however, separated from her husband and eventually gets a divorce.) She and Hart break up and get back together several times.
Hart divides the class into three groups: those who have given up; those who are trying, but fear being called upon in class to respond to Kingsfield's questions; and the "upper echelon". As time goes on, he moves from the second classification to the third. Late one night, Hart and another student break into a secured room of the library and read personal notes Kingsfield had taken when he was a law student.
Charles W. Kingsfield Jr.