In the passage, the narrator describes how their childish experiment of peering into the tarn intensified their initial eerie feeling. They acknowledge that their growing superstition only fueled itself, illustrating a paradox where fear amplifies the emotion it stems from. Which literary principle does this scenario best demonstrate?

Explanation

The passage exemplifies the 'Unity of effect,' a concept where every element of a work contributes to a single emotional impact, often intensifying feelings such as fear or suspense. The narrator’s experience shows how the awareness of growing superstition accelerates the emotional response, perfectly illustrating this principle.