Ideas about language and its relationship with thought and consciousness shape much of the premise and thematic frameworks of The Library at Mount Char. Carolyn, the protagonist, studies the catalog of language, and the librarians speak an invented language known as Pelapi. Author Scott Hawkins suffuses the narrative with made-up words whose meanings are profoundly important to character arc and theme development. The term uzan-iya, for example, describes the moment when an innocent heart first contemplates committing murder, symbolizing an initial moral corruption. The significance of language in the text revolves around the ways humans relate to each other and how a breakdown in these relational connections can harm society.

Hawkins’s exploration of language and abstract concepts like understanding, communicating, and thinking was inspired by natural language processing (NLP), a subfield of computer science and artificial intelligence that aims to bridge the gap between human language and machines. He learned about the Sapir-Whorf hypothesis, which states that the structures of one’s language influence or even determine how one thinks and perceives the world. 

The Sapir-Whorf hypothesis is named after two of its earliest advocates, Edward Sapir and his student Benjamin Lee Whorf. Sapir proposed an early version of the hypothesis in 1929: