Who is Mark Studdock from That Hideous Strength and what is their importance?

Mark is one of the two main characters in this novel. He is a sociologist, and a member of the Progressive Element at Bracton College. He is the husband of Jane Studdock, and his character changes greatly during the course of the novel. In the beginning of the story Mark is inattentive toward Jane, and he is primarily concerned with reaching the inner circle of any social group. He pursues his goal of gaining admittance into these exclusive groups at almost any cost. Mark is a bit prideful when it comes to his importance within these groups, and he is mostly unaware of his need to feel like he belongs.