Roman Jacobson was a Russian linguist whose work was central to the development of Formalism and Structuralism. He analyzed how literary texts use unique forms and structures to inherently convey meaning, without needing detailed context outside the text. Jacobson identified six functions of language that contribute to a message: referential, poetic, emotive, conative, phatic, and metalingual. His influential book "Linguistics and Poetics" applied linguistic theories to the study of literature.