Postmodernist ideas can be seen in philosophy , the analysis of culture and society , literature , architecture , and design . Changes in history , law and culture came in the late 20th century . Postmodernist ideas in philosophy and the analysis of culture and society expanded the importance of critical theory and has been the point of departure for works of literature , architecture , and design , as well as being visible in marketing\/business and the interpretation of history , law and culture , starting in the late 20th century .