Final answer:
Joseph Campbell is known for the 'Hero's Journey' or Monomyth, not 'Single-Source Theory.' His theory suggests many myths share a common structure of various stages in storytelling. By applying Campbell's model to literature and films, one observes universal patterns that pervade stories across different cultures.
Step-by-step explanation:
The term “Joseph Campbell's Single-Source Theory” mentioned in the question appears to be a misunderstanding. Joseph Campbell is renowned for his concept of the 'Hero's Journey,' also known as the Monomyth. It is not referred to as the 'Single-Source Theory.' The Monomyth is the theory that many myths from different cultures and times share a fundamental structure, which involves stages like the Call to Adventure, the Crossing of the First Threshold, the Road of Trials, and others.
These stages form a narrative pattern that storytellers have employed for centuries. It is applicable to a broad range of stories, from ancient legends to modern novels and movies. Identifying these stages in a story, such as an ancient Korean novel, would involve pointing out events like the protagonist receiving a call to action, facing challenges, obtaining a revelation, and returning transformed.
By exerting this analytical approach, one can appreciate the universal patterns in storytelling suggested by Campbell's theory, which serves as a framework for understanding the shared human experience. This concept is often a topic of interest for people interpreting literature, films, and other media content loaded with stories and archetypes.