Hofmann has received more and more attention from scholars and writers on art as time has gone by. This is the essential collection of his lucid and illuminating remarks on art. Hofmann's writings (along with Kandinsky's "Concerning the Spiritual in Art" and other neglected texts) give the lie to the formal aesthetic analysis of art historians who have pigeon-holed abstract expressionism as the species of disruptive innovation that it was and nothing more, when in reality its practitioners had deeply personal philosophical and spiritual concerns. Hofmann believed that the artist must translate his feelings for nature into a creative interpretation of the medium. In other words, "to explore the nature of the medium (i.e., the paint) is part of the understanding of creation, as well as part of the process of creation." So the artist doesn't create a mirror image of nature, but rather the artist communicates an engagement with the essence of things through the creation of art (e.g., a painting) that becomes a shining, transcendent, "spiritual" object in its own right. He took a Hegelian approach - the artist's interior life, plus the medium, creates a "spiritual synthesis" that is a new thing in the world.
Heady stuff, and not for the faint of brain, but if you're not a stranger to philosophy or otherwise willing to explore the nuances of what happens when an artist approaches the canvas (what Hofmann calls "the blending of experience gained in life with the natural qualities of the art medium") then you just found the Artist's Bible for the post-representational world of expression.