Psychologism as a sceptical relativism
There are two respects in which one can here talk of the self-evident ‘conditions of the possibility’ of any theory whatever. One can talk of these in a subjective respect. Here one’s concern is with the a priori conditions upon which the possibility of immediate and mediate knowledge1 depends, as also the possibility of rationally justifying any theory. The theory which validates knowledge is itself a piece of knowledge: its possibility depends on certain conditions, rooted, in purely conceptual fashion, in knowledge and its relation to the knowing subject. It is, e.g. part of the notion of knowledge, in the strict sense, that it is a judgement that does not merely claim to state truth, but is also certain of this claim’s justiﬁcation, and actually possesses the justiﬁcation in question. If the judging person were never in a position to have direct personal experience and apprehension of his judgement’s self-justifying character, if all his judgements lacked that inner evidence which distinguishes them from blind prejudices, and yields him luminous certainties, it would be impossible to provide a rational account and a foundation for knowledge, or to discourse on theory and science. A theory therefore violates the subjective conditions of its own possibility as a theory, when, following our example, it in no way prefers an inwardly evident judgement to a blind one. It thereby destroys the very thing that distinguishes it from an arbitrary, unwarranted assertion.