Jack Tanner is a young man who considers himself to be a forward thinker. He published the Revolutionist’s Handbook (a text that Shaw actually wrote and included in the appendix of the play, attributed to Jack), which has turned him into a paradox. He is a wealthy man with high social standing who has blatantly flouted the social niceties of convention by instructing others to be revolutionary and upset the social hierarchy. Ramsden in particular dislikes Jack, presuming that his ideas are harmful without even deigning to read his book.

Jack is Shaw’s Don Juan character. However, Shaw imagines a Don Juan who has given up the pursuit of women in order to focus on philosophy and what he considers to be a higher purpose. But this leaves a character whose greatest weakness is women and their ability to distract him from his goals. When Jack becomes Ann’s co-guardian, he is afraid of her, sure that she will derail his life and dedication to philosophy. Despite his protestations, she eventually tricks him into marrying her. 

Ramsden is an old family friend of the Whitefields. He believes that he is liberal and progressive, but he strongly dislikes Jack’s ideas.