Time, space and causality, in their whole lawfulness and in the possibility of all their forms, are present in our consciousness wholly independently of the objects that appear in them and make up their content, which, in Schopenhauer's words, we have learned from the great Kant, or in other words can be found as well from the subject as from the object, and can with equal right be called ways of intuiting of the subject or qualities of the object in so far as it is object, that is, representation.
Wir haben von dem großen Kant gelernt, daß Zeit, Raum und Kausalität, ihrer ganzen Gesetzmäßigkeit und der Möglichkeit aller ihrer Formen nach, in unserm Bewußtseyn vorhanden sind, ganz unabhängig von den Objekten, die in ihnen erscheinen, die ihren Inhalt ausmachen, oder mit anderen Worten: daß sie eben sowohl, wenn man vom Subjekt, als wenn man vom Objekt ausgeht, gefunden werden können; daher man sie mit gleichem Recht Anschauungsweisen des Subjekts, oder auch Beschaffenheiten des Objekts, sofern es Objekt (bei Kant: Erscheinung) d. h. Vorstellung ist, nennen kann.
We have learned from the great Kant that time, space and causality, in their whole lawfulness and in the possibility of all their forms, are present in our consciousness wholly independently of the objects that appear in them and make up their content; or in other words: that they can be found just as well when one starts from the subject as when one starts from the object; and so one can with equal right call them ways of intuiting of the subject, or also qualities of the object in so far as it is object (in Kant: appearance), that is, representation.
The first sentence of § 24. The sentence attributes the doctrine to Kant by name, »von dem großen Kant gelernt«, and asserts it; the statement keeps both. It licenses two namings of the forms »mit gleichem Recht«, the subject's ways of intuiting and qualities of the object so far as it is representation, and the link shares_premise_with is set to Kant's A 24 / B 38 (c-kant-space-a-priori), whose statement has space as »nicht als eine von ihnen abhängende Bestimmung«, not a determination dependent on the appearances: the premise the comparison x-thing-in-itself names is that space is not dependent on the objects that appear in it, which both assert, Schopenhauer of time and causality too. No link is set to the claim that space is the subjective condition of sensibility (c-kant-space-subjective-condition-of-sensibility), which words the form's being the subject's and not its independence of the objects. The paragraph's next sentence, the conditional on empty phantoms, is c-schopenhauer-objects-not-empty-phantoms-must-point-to-thing-in-itself; the second paragraph of § 24 draws from this sentence's doctrine, »Denn da das Subjekt sie aus sich selbst ... vollständig erkennt und konstruirt«, what Kant »richtig geschlossen«, that the forms are not determinations of the thing in itself (c-schopenhauer-kant-rightly-concluded-forms-not-determinations-of-thing-in-itself), where a link is set; that step is not formalized.