The modern age began in the late 15th century when Europe had influence over land and people not its own. Post modernism began in the late 20th Century. It was recognized that there are 'others' and that in fact, we are an 'other'. Our western culture is neither as homogeneous nor as monolithic as we once believed it to be. In regard to art, modern art theorists had put forward the idea that 'form' is more important than 'content' and that taste is universal and shared by all. Postmodern art theory deconstructs this claim.
ideas taken from "the discourse of others" by Craig Owens