In "Lost in the Cosmos: The Last Self-Help Book," Walker Percy discusses the importance of semiotics, or the study of signs and symbols, in understanding the nature of language and reality. He argues that language is inherently social and requires interaction with others to acquire meaning. For instance, one must see an apple and hear it named before recognizing its existence, illustrating that knowledge is not solely an individual experience.

By emphasizing the social roots of language, Percy suggests that semiotics helps us break free from solipsism, the philosophical idea that only one's own mind is sure to exist. He posits that this framework fosters a recognition of a shared reality, where objects like apples exist independently of our perceptions. Thus, semiotics is crucial for connecting individuals to a collective world and understanding the interdependencies of meaning and existence.