The word 原因 is formed by combining two characters, each contributing a related meaning to create a unified concept. 原 (yuán) carries the sense of "source", "origin", or "root", picturing the foundational starting point. 因 (yīn) means "cause", "reason", or "basis", focusing on the logical factor that brings about an effect. Their combination merges these overlapping ideas of origin and causation, creating a single, reinforced term for the fundamental reason or cause of something.