In "The Origin and Progress of Language" Burnett analysed the structure of languages, and argued that humans had evolved language skills in response to changing environment and social structures. Burnett was the first to note that some languages create lengthy words for rather simple concepts. He reasoned that in early languages there was an imperative for clarity, so that redundancy was built in and seemingly unnecessary syllables added. He concluded that this form of language evolved when clear communication might be the determinant of avoiding danger.