“All of our descriptive statements move within an often invisible network of value-categories, and indeed without such categories we would have nothing to say to each other at all. It is not just as though we have something called factual knowledge which may then be distorted by particular interests and judgements, although this is certainly possible; it is also that without particular interests we would have no knowledge at all, because we would not see the point of bothering to get to know anything. Interests are constitutive of our knowledge, not merely prejudices which imperil it. The claim that knowledge should be 'value-free' is itself a value-judgement.”