Society's Worship of Money
Gordon, the protagonist of the book, believes that society judges everyone by the amount of money that they make, and by the things that they have accumulated. Gradually, this turns into a resentment of money and the power it has over people. Gordon therefore decides to get his own back on money by having none of it, and showing that he can live a perfectly decent life in poverty. The only trouble with this plan is that he can't live a decent life in poverty; he lives a horrible life, and each time he becomes worse off financially, his life experience deteriorates.
Gordon also feels that if he had more money he would be more attractive to women, and to people in general. It doesn't seem to occur to him that it is his personality that alienates women, and people in general. He manages to avoid introspection all together by blaming his unpopularity on his lack of money.
Class System in Britain
The title of the novel is a jab at the importance of the class system in Britain, Each class, specifically defined, has its own idiosyncracies and stereotypes. In the case of the lower middle classes, they are identified by their mock Victorian houses and the large aspidistra plant visible in the front window.
Gordon is also an example of the class system as he comes from a wealthy, upper class family. Unfortunately, their financial star has faded and their "old money" has all but gone, forcing Gordon and his sister to get jobs in order to get by. This is another cause of Gordon's resentment, and his view of the class system is colored by his sense of entitlement and his anger that his family have frittered away his inheritance. To Gordon, working in an advertising agency is horribly middle class, but at the end of the novel he stereotypes himself by moving into a Victorian home and purchasing an aspidistra for the living room.
Women's Propriety
There is a very clear line in the novel between "good girls" and "bad girls". Neither Rosemary's nor Gordon's landladies will allow visitors of the opposite sex to visit their lodgers in their rooms, and Rosemary refuses to sleep with Gordon for a long time, because they are not married. Eventually, she relents, but becomes pregnant.
Gordon then realizes that if he does not marry Rosemary, she will be ostracized by her family for being pregnant outside of marriage. There is an enormous double standard in the way in which women and men were viewed at this time; there is shame in being an unwed mother, like Rosemary is possibly going to become, but not in being the unwed father, like Gordon. This is an example of how men and women were judged differently, and of the way in which women's propriety was seen as far more important than their desires or feelings.
