Is Painting a window to the world or to the soul?

This question has been on my mind lately as I contemplate painting from "life" , or from a photographic source, or from my doodles. What is it that makes an artist's work valuable?
Coincidentally my lover gifted me a valentine, a hard to find book of David Hockney's works called, A Bigger Picture, that addresses just such questions. Hockney is one of my favorite artists and this is the first book of his I have ever owned. It is a luscious testament to landscape, celebrating an artist's viewpoint in watercolor, oil, iPad drawing and film.

Hockney's Pearblossom Highway is a shifting collage that walks us through the landscape

His digital drawings combine collage and stylus work to create surreal personal landscapes

I would love to own Hockney's Secret Knowledge, a controversial book he produced after years of studying old master paintings. He argues that artists since the 1400's knew of the camera lens tricks, way before the chemical process of photography was invented. After studying perspective and camera lens usage, and acknowledging the use of cameras in much of his work, Hockney, in his 70's, shifted to depicting the landscape through a more eastern perspective of multiple viewpoints, opening up and converging with the viewer.

Look how many brushes!!! Each color has its own...that is how his work stays so vibrant and clean.

Hockney also works from life more, quickly capturing a fleeting season or ray of sunlight and then he returns to his studio to repaint the image from memory. I know from experience that the image changes when working like that. We can not look at anything without bringing our personal memory to it.  And our memory edits and highlights it's own details as part of our selective mental storage process. These works, windows to the world and to the soul, are the true gift of Hockney to us.

Painting a scene he knows well, Totem, but from memory... simplified details, highlights the celestial

I just missed him teaching at CU by 15 years, darn it!