To be rational is not the same as to be reasonable.

If science could comprehend all phenomena so that eventually in a thoroughly rational society human beings became as predictable as cogs in a machine, then man, driven by this need to know and assert his freedom, would rise up and smash the machine.

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.

let your aim be to come at truth, not to conquer your opponent. So you never shall be at a loss in losing the argument, and gaining a new discovery.

He was a convinced but hardworked rationalist, always hard at it re-convincing himself of his convictions.

Liberalism is Rationalism in politics.