The term ‘anti-realism’ is ugly enough to scare away the faint hearted; but it is at least as well established as any of the suggested alternatives: irrealism, internalism (which has another very different meaning), perspectivism, conceptual relativism, and so forth. It is widely agreed that Kant is the paradigmatic anti-realist. 2 Always lurking in the background of current debates is his Copernican revolution according to which instead of assuming ‘that all our knowledge must conform to objects’ we should suppose ‘that objects must conform to our knowledge’. 3 In other words, how we take what is given to us determines what gets through to us. Think, for example, of the colour-blind perceiver, or the racist.