"See the exquisite contrast of the types of mind! The pragmat..." — William James quote meaning

See the exquisite contrast of the types of mind! The pragmatist clings to facts and concreteness, observes truth at its work in particular cases, and generalises. Truth, for him, becomes a class-name for all sorts of definite working-values in experience. For the rationalist it remains a pure abstraction, to the bare name of which we must defer. When the pragmatist undertakes to show in detail just why we must defer, the rationalist is unable to recognise the concretes from which his own abstraction is taken. He accuses us of denying truth; whereas we have only sought to trace exactly why people follow it and always ought to follow it. Your typical ultra-abstractions fairly shudders at concreteness: other things equal, he positively prefers the pale and spectral. If the two universes were offered, he would always choose the skinny outline rather than the rich thicket of reality. It is so much purer, clearer, nobler.