Yet there are certain disadvantages attached to a priori categories. They have a certain rigidity, appalling to those who have not learned to identify stiffness with force. Empirical matters are subject to revision. The strongest belief that claims the support of experience is subject to modification when experience testifies against it. But an a priori conception is not open to adverse evidence. There is no court having jurisdiction.
If, then, an unfortunate mortal should happen to be imposed upon so that he was led to regard a prejudice or predilection as an a priori truth, contrary experience would have a tendency to make him the more obstinate in his belief. History proves what a dangerous thing it has been for men, when they try to impose their will upon other men, to think of themselves as special instruments and organs of Deity. The danger is equally great when an a priori Reason is substituted for a Divine Providence. Empirically grounded truths do not have a wide scope; they do not inspire such violent loyalty to themselves as ideas supposed to proceed directly from reason itself. But they are discussable; they have a humane and social quality, while truths of pure reason have a paradoxical way, in the end, of escaping from the arbitrament of reasoning. They evade the logic of experience, only to become, in the phrase of a recent writer, the spoil of a "logic of fanaticism." Weapons forged in the smithy of the Absolute become brutal and cruel when confronted by merely human resistance.
The stiffly constrained character of an a priori Reason manifests itself in another way. A category
of pure reason is suspiciously like a pigeonhole. An American writer, speaking before the present war, remarked with witty exaggeration that "Germany is a monstrous set of pigeonholes, and every mother's son of a German is pigeoned in his respective hole—tagged, labeled and ticketed. Germany is a huge human check-room, and the government carries the checks in its pocket." John Locke's deepest objection to the older form of the a priori philosophy, the doctrine of innate ideas, was the readiness with which such ideas become strongholds behind which authority shelters itself from questioning. And John Morley pointed out long ago the undoubted historic fact that the whole modern liberal social and political movement has allied itself with philosophic empiricism. It is hard here, as everywhere, to disentangle cause and effect. But one can at least say with considerable assurance that a hierarchically ordered and subordered State will feel an affinity for a philosophy of fixed categories, while a flexible democratic society will, in its crude empiricism, exhibit loose ends.
There is a story to the effect that the good townspeople of Königsberg were accustomed to
their watches by the time at which Kant passed upon his walks—so uniform was he. Yielding to the Teutonic temptation to find an inner meaning in the outer event, one may wonder whether German thought has not since Kant's time set its intellectual and spiritual clocks by the Kantian standard: the separation of the inner and the outer, with its lesson of freedom and idealism in one realm, and of mechanism, efficiency and organization in the other. A German professor of philosophy has said that while the Latins live in the present moment, the Germans live in the infinite and ineffable. His accusation (though I am not sure he meant it as such) is not completely justified. But it does seem to be true that the Germans, more readily than other peoples, can withdraw themselves from the exigencies and contingencies of life into a region of Innerlichkeit which at least seems boundless; and which can rarely be successfully uttered save through music, and a frail and tender poetry, sometimes domestic, sometimes lyric, but always full of mysterious charm. But technical ideas, ideas about means and instruments, can readily be externalized because the outer world is in truth their abiding home.