without it; he likewise overlooked the fact, that all derivation à priori, nay, all demonstration whatsoever, rests upon a necessity, and that all necessity itself rests entirely and exclusively on the Principle of Sufficient Reason, be cause to be necessary, and to result from a given reason, are convertible terms; that the Principle of Sufficient Reason is still nothing but the common form of the Object as such: therefore that it always presupposes the Object and does not, as valid before and independently of it, first introduce it, and cannot make the Object arise in conformity with its own legislation. Thus this starting from the Object and the above-mentioned starting from the Subject have in common, that both presuppose what they pretend to derive: i.e., the necessary correlate of their starting-point."
This last assertion" that the Principle of Sufficient Reason already presupposes the Object, but does not, as valid before and independently of it, first introduce it, and cannot make the Object arise in conformity with its own legislation," seemed to me so far to clash with the proof given by Schopenhauer in § 21 of the "Fourfold Root," as, according to the latter, it is the function of the Subject's understanding which primarily creates the objective world out of the subjective feelings of the sensuous organs by the application of the Principle of Sufficient Reason; so that all that is Object, as such, after all comes into being only in conformity with the Principle of Sufficient Reason, consequently that this principle cannot, as Schopenhauer asserted in his polemic against Fichte, already presuppose the Object. In 1852, therefore, I wrote as follows to Schopenhauer:—
"In your arguments against Fichte, where you say that the Principle of Sufficient Reason already presupposes the Object, and cannot, as valid before and independently of it, first introduce it, the objection occurred to me anew, that in your "Fourfold Root" you had made the Object of per-
