 In Poincaré’s view, we only know the distance from one point to another on the basis of experience with rigid bodies, and this knowledge has become innate in us. In Russell’s view, distance is to be regarded as a fundamental intuition, and if some contemplated that the distance from London to Paris could be less than a metre, we would know we could not be talking about distance. But Poincaré insisted that talk of what we know should always be dependent on how we know it; without that, the claims were not knowledge claims at all.