Hegel is like reading gibberish but Schopenhauer really isn't much better. Here is a random part of 'world as will and spirit'

"Whatever the thing-in-itself may be, Kant is right in his conclusion that time, space, and causality (which we afterwards found to be forms of the principle of sufficient reason, the general expression of the forms of the phenomenon) are not its properties, but come to it only after, and so far as, it has become idea. That is, they belong only to its phenomenal existence, not to itself. For since the subject fully understands and constructs them out of itself, independently of all object, they must be dependent upon existence as idea as such, not upon that which becomes idea. They must be the form of the idea as such; but not qualities of that which has assumed this form. They must be already given with the mere antithesis of subject and object [156] (not as concepts but as facts), and consequently they must be only the more exact determination of the form of knowledge in general, whose most universal determination is that antithesis itself. Now, that in the phenomenon, in the object, which is in its turn conditioned by time, space and causality, inasmuch as it can only become idea by means of them, namely multiplicity, through co-existence and succession, change and permanence through the law of causality, matter which can only become idea under the presupposition of causality, and lastly, all that becomes idea only by means of these,—all this, I say, as a whole, does not in reality belong to that which appears, to that which has passed into the form of idea, but belongs merely to this form itself. And conversely, that in the phenomenon which is not conditioned through time, space and causality, and which cannot be referred to them, nor explained in accordance with them, is precisely that in which the thing manifested, the thing-in-itself, directly reveals itself. It follows from this that the most complete capacity for being known, that is to say, the greatest clearness, distinctness, and susceptibility of exhaustive explanation, will necessarily belong to that which pertains to knowledge as such, and thus to the form of knowledge; but not to that which in itself is not idea, not object, but which has become knowledge only through entering these forms; in other words, has become idea, object. Thus only that which depends entirely upon being an object of knowledge, upon existing as idea in general and as such (not upon that which becomes known, and has only become idea), which therefore belongs without distinction to everything that is known, and which, on that account, is found just as well if we start from the subject as if we start from the object,—this alone can afford us without reserve a sufficient, exhaustive knowledge, a knowledge which is clear to the very foundation. But this consists of nothing but those forms of all [157] phenomena of which we are conscious a priori, and which may be generally expressed as the principle of sufficient reason. Now, the forms of this principle which occur in knowledge of perception (with which alone we are here concerned) are time, space, and causality. The whole of pure mathematics and pure natural science a priori is based entirely upon these. Therefore it is only in these sciences that knowledge finds no obscurity, does not rest upon what is incomprehensible (groundless, i.e., will), upon what cannot be further deduced. It is on this account that Kant wanted, as we have said, to apply the name science specially and even exclusively to these branches of knowledge together with logic. But, on the other hand, these branches of knowledge show us nothing more than mere connections, relations of one idea to another, form devoid of all content. All content which they receive, every phenomenon which fills these forms, contains something which is no longer completely knowable in its whole nature, something which can no longer be entirely explained through something else, something then which is groundless, through which consequently the knowledge loses its evidence and ceases to be completely lucid. This that withholds itself from investigation, however, is the thing-in-itself, is that which is essentially not idea, not object of knowledge, but has only become knowable by entering that form. The form is originally foreign to it, and the thing-in-itself can never become entirely one with it, can never be referred to mere form, and, since this form is the principle of sufficient reason, can never be completely explained. If therefore all mathematics affords us an exhaustive knowledge of that which in the phenomena is quantity, position, number, in a word, spatial and temporal relations; if all etiology gives us a complete account of the regular conditions under which phenomena, with all their determinations, appear in time and space, but, with it all, teaches us nothing more than why in each case this particular phenomenon must appear just at [158] this time here, and at this place now; it is clear that with their assistance we can never penetrate to the inner nature of things.