Final answer:
The author quotes Aristotle's definition of comedy to highlight its contrasting nature with tragedy and emphasize its aim to inspire mockery and ridicule.
Step-by-step explanation:
Aristotle's definition of comedy is quoted by the author because it contrasts with his analysis of tragedy and highlights the different purposes and effects of the two genres. According to Aristotle, tragedy evokes pity and fear in the audience, leading to a purging of emotions through a process called catharsis.
In contrast, comedy aims to inspire mockery and ridicule of the failings of others, providing entertainment rather than a cathartic experience. By quoting Aristotle's definition, the author emphasizes the distinct characteristics and goals of comedy.