If the basic assumption of the theory of ideology is at all tenable, namely, that the general power relations embodied in our social structures can exert a distorting influence on the formation of our beliefs and preferences without our being aware of it, then we are definitely not going to put that kind of influence out of action by asking the agents in the society to imagine that they didn't know their position. To think otherwise is to believe in magic: imagine you are impartial and you will be. In fact, doing that will be more likely to reinforce the power of these entrenched prejudices because it will explicitly present them as universal, warranted by reason, etc.

pp. 88-89. - Philosophy and Real Politics (2008)