Final answer:
A character suffering from heart disease is an effective metaphorical device because it symbolically represents deep emotional or psychological stress and can evoke empathy from the audience, highlighting broader societal issues or personal struggles.
Step-by-step explanation:
Foster suggests that a character suffering from heart disease serves as an ideal metaphorical device because it symbolizes deeper emotional or psychological strife. The heart itself is often associated with the core of a person -- their feelings, desires, and soul. When an author uses heart disease as a metaphor, it can suggest that a character is undergoing intense emotional stress or deprivation, much like pathos appeals to the audience's emotions in literature and art. This metaphor is powerful as it connects the physical condition of the heart to the character's existential experience and can be used to reflect broader societal issues, as seen in the works of Desmond and the portrayal of personal turmoil in The Two Fridas. Conditions like heart disease mirror the intensity of the character's struggles and can evoke empathy from the audience, similar to the scene of suffering in Greek tragedy, adding layers of meaning to a character's journey.