Isabella Thorpe and Catherine Morland comprise the most prominent pair of foils in Northanger Abbey. They are the same age, they both have older brothers, and they both love Gothic fiction. But the similarities end there. Isabella is selfish, shallow, and fickle. Catherine, on the other hand, is kind and generous. Isabella also has many so-called friends, but she's far more concerned with monetary gain. Catherine, who has rarely been outside her home, has not had the chance to accumulate a large social circle. In Volume 1, Chapter 6, Isabella claims that she would do anything for her friends:
There is nothing I would not do for those who are really my friends. I have no notion of loving people by halves, it is not my nature. My attachments are always excessively strong. I told Capt. Hunt at one of our assemblies this winter, that if he was to tease me all night, I would not dance with him, unless he would allow Miss Andrews to be as beautiful as an angel. The men think us incapable of real friendship you know, and I am determined to shew them the difference.
Here, Isabella expresses her "excessively strong" attachment to her friends in hopes of bettering her relationship with Catherine. However, her main motive is to charm Catherine so that she can develop a relationship with her brother James. Most importantly, Isabella is clever and manipulative, whereas Catherine is completely artless. She rarely reveals her true motive, whereas Catherine always says exactly what she thinks and feels.
