Which word describes someone who remains unaffected by passion or feeling?

The word "stoic" describes a person who remains unaffected by passion or feeling, embodying a sense of calm indifference towards pleasure or pain. This term is derived from Stoicism, an ancient Greek philosophy that teaches the development of self-control and fortitude as a means of overcoming destructive emotions. A stoic person tends to maintain a rational perspective, showing resilience in the face of life's difficulties, and is considered unflappable, which aligns with the definition of being unaffected by strong emotions.

The other options do not convey the same meaning. "Mundane" refers to something ordinary or lacking excitement, which does not specifically relate to emotional detachment. "Erratic" describes behavior that is unpredictable or inconsistent, stemming from fluctuating emotions rather than a stoic demeanor. "Paucity" denotes the presence of something in insufficient quantity, which is unrelated to emotional response or feeling. Therefore, "stoic" is the most appropriate choice for someone who remains unaffected by passion or feeling.