Charles Stevenson was an influential American philosopher known for his work in the field of ethics and the philosophy of language. He is best recognized for his development of the theory of emotivism, which suggests that moral statements express emotional attitudes rather than factual claims. His ideas contributed significantly to the understanding of how language functions in moral discourse. Stevenson was also a prominent figure in the Pragmatism movement, which emphasizes the practical consequences of beliefs and ideas. His writings explored the relationship between language, meaning, and human behavior, making him a key figure in 20th-century philosophy.