The Vedantic perspective is that Consciousness is not understandable in a “subject-object” manner because it is the ultimate subject of all understandings which are objects appearing in Consciousness.
Itself, it cannot be objectified and understood thus.
There is a way of “knowing” it (Enlightenment) but this does not occur in the subject-object mode and thus this knowledge is not transferrable through language or symbols.
My understanding, prior to briefly reading that paper, was that Schopenhauer came up with the core of his philosophy before he came across the upanishads. When he did read them, he was delighted to find that they contained many of the same ideas that he had arrived at independently. He saw this as evidence for the deep truths in his own thinking.
Whatever the true genealogy of the ideas, I think there is a considerable convergence of thought in trying to solve the same problems.
If memory serves, he does mention in the preface to “The World as Will and Representation” that the Vedic scholar would be best placed to understand what he is trying to say
Itself, it cannot be objectified and understood thus.
There is a way of “knowing” it (Enlightenment) but this does not occur in the subject-object mode and thus this knowledge is not transferrable through language or symbols.