Summing up 1200+ pages of Schopenhauer with 2 simple concepts™

Arthur Schopenhauer's "On The Fourfold Root Of The Principle Of Sufficient reason" and "The World As Will And Representation" can be explained with this picture:

And this conceptual embodiment of the Vedic elements (Schopenhauer's Mentor and friend was Goethe, A lover of eastern literature):

Earth: Everything empirical, represents things as they appear to us under sensory illusion

Water: Everything that has to do with the understanding; the passive pool of experience

Fire: Everything that has to do with reason, creation, deeply related to water, what compares and contrasts new information

Wind: The will, the thing-in-itself, the ever invisible yet ever pervasive aspect of the self

At any given second all of these "Elements" are acting in rapid fire succession with one another to embody a thought, action, or state of being

These are the precepts behind perception

In Vedic thought the use of all 4 elements was a type of prayer; like the preparations of medicines, cooking, sacrifice, etc...
Hence every thought, action, and feeling is an abstracted microcosm of a prayer