 Richard Montague was a mathematical logician who had specialized in set theory and modal logic. His views on natural language must be understood with his mathematical background in mind. Montague held the view that natural language was a formal language very much in the same sense as predicate logic was a formal language. As such, in Montague’s view, the study of natural language belonged to mathematics, and not to psychology (Thomason 1974, 2). Montague formulated his views: