II THE FUNDAMENTAL PROBLEM OF KANT’S THEORY OF KNOWLEDGE
Reinhold Friedrich Alfred Hoernlé translation
The other objection lies in this, that we have no right, at the outset of our epistemological investigations, to affirm that no absolutely certain knowledge can have its source in experience. Without doubt, it is easily conceivable that experience itself might contain a criterion guaranteeing the certainty of all knowledge which has an empirical source.
Thus, Kant’s formulation of the problem implies two presuppositions. The first is that we need, over and above experience, another source of cognitions. The second is that all knowledge from experience has only conditional validity. Kant entirely fails to realise that these two propositions are open to doubt, that they stand in need of critical examination. He takes them over as unquestioned assumptions from the dogmatic philosophy of his predecessors and makes them the basis of his own critical inquiries. The dogmatic thinkers assume the validity of these two propositions and simply apply them in order to get from each the kind of knowledge which it guarantees. Kant assumed their validity and only asks, What are the conditions of their validity? But, what if they are not valid at all? In that case, the edifice of Kantian doctrine lacks all foundation whatever.
The propositions that we really have knowledge which is independent of all experience, and that experience can furnish knowledge of only relative universality, could be accepted by us as valid only if they were conclusions deduced from other propositions. It would be absolutely necessary for these propositions to be preceded by an inquiry into the essential nature of experience, as well as by another inquiry into the essential nature of knowing. The former might justify the first, the latter the second, of the above two propositions.