’Anyway, what is indisputable in what we’re saying’, I said, ‘is that dialectic is the only field of enquiry which sets out methodically to grasp the reality of any and every thing. All the other areas of expertise, on the other hand, are either concerned with fulfilling people’s beliefs and desires, or are directed towards the generation and manufacture or looking after things while they’re being generated and manufactured. Even any that are left—geometry and so on, which we were saying do grasp reality to some extent—are evidently dreaming about reality. There’s no chance of their having a conscious glimpse of reality as long as they refuse to disturb the things they take for granted and remain incapable of explaining them. For if your starting-point is unknown, and your end-point and intermediate stages are woven together out of unknown material, there may be coherence, but knowledge is completely out of the question.’ —Plato, Republic, 533b–c (trans. R. Waterfield)