@ Broca 10:13 Dec 3, 2012
You are quite right. "Postmodern" and "postmodernist" often appear to be used interchangeably, even by specialists. Indeed, in the source you have just cited, which should be reliable, both "postmodern theory" and "postmodernist theory" occur, the former more times than the latter. However, my personal view that the two terms can and ideally should be distinguished along the lines I indicated, even though the distinction is often difficult to establish in particular cases: a postmodern theory, in principle, is a theory that is postmodern in its nature, characterised by features that it shares with postmodern intellectual and cultural phenomena, whereas a postmodernist theory is one that involves some kind of intellectual commitment to the cultural and intellectual approach known as postmodernism. | 
peer agreement (net): +6