Synthesized answer
Schopenhauer insists on knowing Kant first because he believes a thorough knowledge of Kant's philosophy is the indispensable condition for a right comprehension of his own meaning [5]. He views his own work, particularly the "Fourfold Root," as a key to his system, built upon the foundation of Kant's philosophy [5].
Schopenhauer suggests that Kant's work has been influential but that he has found Kant's view to be "extremely erroneous" and that he had to "clear the way" to illuminate the mechanism of our knowledge [1]. He believes his own rectification of Kant's ideas does not diminish but rather enhances Kant's fundamental idealistic position [1]. Additionally, he indicates that his "Fourfold Root" finds its completion in his Critique of Kantian Philosophy [3].
Synthesized from the book passages below. Chat with the book on Feynman for follow-up.
From the book
ant's work, in order to convince themselves of the far greater accuracy of my view of the whole process and connection. Kant's extremely erroneous view has held its ground till now in philosophical literature, simply because no one ventured to attack it; therefore I have found it necessary to clear the way in order to throw light upon the mechanism of our knowledge. [92] Kant, "Krit. d. r. V." 1st edition, p. 367 _sqq._ (English translation by M. Müller, p. 318 _sqq._) [93] Kant, "Krit. d. r. Vern." 1st edition, p. 371. (English translation, by M. Müller, p. 322.) [94]…
o his own system, asserting that knowledge to be the indispensable condition for a right comprehension of his meaning. So far as I am aware, neither the "Fourfold Root" nor the "Will in Nature" have as yet found a translator; therefore, considering the dawning interest which has begun to make itself felt for Schopenhauer's philosophy in England and in America, and the fact that no more competent scholar has come forward to do the work, it may not seem presumptuous to suppose that this version may be acceptable to those who wish to acquire a more than superficial knowledge of…
ould not do here what I had done in my chief work, that is, give the later additions I had made in a separate appendix. Besides, it is of no consequence that people should know what I wrote in my twenty-sixth and what in my sixtieth year; the only matter of real importance is, that those who wish to find their way through the fundamental principles of all philosophizing, to gain a firm footing and a clear insight, should in these few sheets receive a little volume by which they may learn something substantial, solid, and true: and this, I hope, will be the case. From the expansion now…
nd before all things in heaven and on earth, is the Principle of Sufficient Reason in the form of the Law of Causality. For it is a _veritas æterna_: _i.e._ it is in and by itself above Gods and Fate; whereas everything else, the understanding, for instance, which thinks that principle, and no less the whole world and whatever may be its cause--atoms, motion, a Creator, _et cætera_--is what it is only in accordance with, and by virtue of, that principle. Hume was the first to whom it occurred to inquire whence this law of causality derives its authority, and to demand its credentials.…
e the public, I am aware of the great difficulties of my task, and indeed can hardly hope to do justice to the Author. In fact, had it not been for the considerations I am about to state, I might probably never have published what had originally been undertaken in order to acquire a clearer comprehension of these essays, rather than with a view to publicity. [1] From the fourth edition by Julius Frauenstädt. "Fourfold Root," Leipzig, 1875; "Will in Nature," Leipzig, 1878. The two treatises which form the contents of the present volume have so much importance for a profound and…