The desire for wealth does motivate Catherine's marriage, which results in Heathcliff's flight and causes him to acquire Wuthering Heights, to appropriate Thrushcross Grange, and to dispossess Hareton. Is it possible that one of the other themes constitutes the center of the novel, or are the other themes secondary to the theme of love? Consider the following themes: Clash of elemental forces. The universe is made up of two opposite forces, storm and calm. Wuthering Heights and the Earnshaws express the storm; Thrushcross Grange and the Lintons, the calm. Catherine and Heathcliff are elemental creatures of the storm.
This theme is discussed more fully in Later Critical response to Wuthering Heights The clash of economic interests and social classes. The novel is set at a time when capitalism and industrialization are changing not only the economy but also the traditional social structure and the relationship of the classes. The yeoman or respectable farming class (Hareton) was being destroyed by the economic alliance of the newly-wealthy capitalists (Heathcliff) and the traditional power-holding gentry (the Lintons). This theme is discussed more fully in Wuthering Heights as Socio-Economic Novel.