The Will to Power · Friedrich Wilhelm Nietzsche
530.
Kant's theological bias, his unconscious dogmatism, his moral outlook, ruled, guided, and directed him. The πρῶτον ψεῡδος: how is the fact knowledge possible? Is knowledge a fact at all? What is knowledge? If we do not _know_ what knowledge is, we cannot possibly reply to the question, Is there such a thing as knowledge? Very _fine!_ But if I do not already "know" whether there is, or can be, such a thing as knowledge, I cannot reasonably ask the question, "What is knowledge?" Kant _believes_ in the fact of knowledge: what he requires is a piece of _naïveté: the knowledge of knowledge!_ "Knowledge is judgment." But judgment is a belief that something is this or that! And not knowledge! "All knowledge consists in synthetic judgments" which have the character of being _universally true_ (the fact is _so_ in all cases, and does not change), and which have the character of being _necessary_ (the reverse of the proposition cannot be imagined to exist). The _validity_ of a belief in knowledge is always taken for granted; as is also the _validity_ of the feelings which conscience dictates. Here _moral ontology_ is the _ruling_ bias. The conclusion, therefore, is: (1) there are propositions which we believe to be universally true and necessary. (2) This character of universal truth and of necessity cannot spring from experience.
(3) Consequently it must base itself upon no experience at all, _but upon something else_, it must be derived from another source of knowledge! Kant concludes (1) that there are some propositions which hold good only on one condition; (2) this condition is that they do not spring from experience, but from pure reason. Thus, the question is, whence do we derive our reasons for _believing_ in the truth of such propositions? No, whence does our belief get its cause? But the _origin of a belief,_ of a strong conviction, is a psychological problem: and very limited and narrow experience frequently brings about such a belief! _It already presupposes_ that there are not only "data _a posteriori_" but also "data _a priori_"-- that is to say, "previous to experience." Necessary and universal truth cannot be given by experience: it is therefore quite clear that it has come to us without experience at all? There is no such thing as an isolated judgment! An isolated judgment is never "true," it is never knowledge; only in _connection with,_ and when _related to,_ many other judgments, is a guarantee of its truth forthcoming. What is the difference between true and false belief? What is knowledge? He "knows" it, that is heavenly! Necessary and universal truth cannot be given by experience! It is therefore independent of experience, _of_ all experience! The view which comes quite _a priori,_ and therefore independent of all experience, _merely out of reason,_ is "pure knowledge"!
"The principles of logic, the principle of identity and of contradiction, are examples of pure knowledge, because they precede all experience."--But these principles are not cognitions, but _regulative articles of faith._ In order to establish the _a priori_ character (the pure rationality) of mathematical axioms, space _must be conceived as a form of pure reason._ Hume had declared that there were no _a priori_ synthetic judgments. Kant says there are--the mathematical ones! And if there are such judgments, there may also be such things as metaphysics and a knowledge of things by means of pure reason! Mathematics is possible under conditions which are _not_ allowed to metaphysics. All human knowledge is either experience or mathematics. A judgment is synthetic--that is to say, it co-ordinates various ideas. It is _a priori_--that is to say, this co-ordination is universally true and necessary, and is arrived at, not by sensual experience, but by pure reason. If there are such things as _a priori_ judgments, then reason must be able to co-ordinate: co-ordination is a form. Reason must _possess a formative faculty._
Text from Project Gutenberg, public domain in the United States.