Plurality is conditioned by time and space, the principium individuationis, which are only our form of cognition and no property of the thing in itself
Plurality in general is necessarily conditioned by time and space and thinkable only in them, which in this respect are called the principium individuationis; and time and space are shapes of the principle of sufficient reason, in which all our cognition a priori is expressed, and that cognition, as set out above, precisely as such belongs only to the cognizability of things, not to the things themselves, that is, is only our form of cognition, not a property of the thing in itself, which as such is free of every form of cognition, even that of being object for the subject.
Wir wissen, daß die Vielheit überhaupt nothwendig durch Zeit und Raum bedingt und nur in ihnen denkbar ist, welche wir in dieser Hinsicht das principium individuationis nennen.
We know that plurality in general is necessarily conditioned by time and space and is thinkable only in them, which in this respect we call the principium individuationis.
Zeit und Raum aber haben wir als Gestaltungen des Satzes vom Grunde erkannt, in welchem Satz alle unsere Erkenntniß a priori ausgedrückt ist, die aber, wie oben auseinandergesetzt, eben als solche, nur der Erkennbarkeit der Dinge, nicht ihnen selbst zukommt, d. h. nur unsere Erkenntnißform, nicht Eigenschaft des Dinges an sich ist, welches als solches frei ist von aller Form der Erkenntniß, auch von der allgemeinsten, der des Objektseyns für das Subjekt, d. h. etwas von der Vorstellung ganz und gar Verschiedenes ist.
But we have recognized time and space as shapes of the principle of sufficient reason, in which principle all our cognition a priori is expressed, and this cognition, however, as set out above, precisely as such belongs only to the cognizability of things, not to the things themselves, that is, is only our form of cognition, not a property of the thing in itself, which as such is free of every form of cognition, even of the most general, that of being object for the subject, that is, is something altogether different from the representation.
The first two sentences of § 25, which the argument a-schopenhauer-will-knows-no-plurality takes as its one textual premise. The second sentence refers back, »wie oben auseinandergesetzt«, to § 23 (c-schopenhauer-will-free-of-forms-of-appearance) and § 24 (c-schopenhauer-kant-rightly-concluded-forms-not-determinations-of-thing-in-itself), and it asserts of space what Kant's A 26 / B 42 asserts, »nicht Eigenschaft des Dinges an sich« beside Kant's »keine Eigenschaft irgend einiger Dinge an sich« (c-kant-space-not-of-things-in-themselves); the map sets the shares_premise_with link on § 23 and on the § 24 sentence that names Kant, where the doctrine is stated, and not here, where it is recalled by »wie oben auseinandergesetzt«; the comparison says so, and a reader may ask for it. »Erkennbarkeit« is rendered »cognizability«, »Erkenntnißform« »form of cognition«.