It's an awful phrase, you know, when you stop to think about it: "Devil's advocate." Yet how often have we heard people use it? Indeed, how often have we taken it and applied it to ourselves? "I just want to play devil's advocate," we say, and by that we mean that we want to present a contrary point of view.
Taken literally, however, that familiar figure of speech suggests a terrible prospect. The image is this: "If the devil were here, this is what I would think he would say. I want to speak in his place. I want to be an advocate for his point of view."