Structuralism is a 20th century intellectual movement inaugurated by Claude Levi-Strauss that sought to understand works of art and human activities through their underlying structures. It holds that human perception and thought are constructed by systems like language, which have elements that exist in relation to one another based on rules rather than nature. According to structuralism's founder Ferdinand de Saussure, language operates at two levels - langue as the whole system that precedes speech, and parole as actual utterances. A sign in language is an arbitrary combination of a signifier and signified, with meaning derived through their differences from other signs.