The task of philosophy, often a difficult and painful one, is to extricate and bring to light the hidden categories and models in terms of which human beings think, to reveal what is obscure or contradictory in them, to discern the conflicts between them that prevent the construction of more adequate ways of organising and describing and explaining experience (for all description as well as explanation involves some model in terms of which the describing and explaining is done); and then, at a still ‘higher’ level, to examine the nature of this activity itself (epistemology, philosophical logic, linguistic analysis), and to bring to light the concealed models that operate in this second-order, philosophical, activity itself. – Isaiah Berlin