Rudolf Steiner’s articles and essays are a wealth of information. As a for instance, here are seven essays on Art and Aesthetics from the collected work, Methodological Foundations of Anthroposophy 1884-1901, Bibliography No. 30. There are two essays on Herman Grimm, one essay each on Tolstoy and Franz Brentano, and selected articles on Beauty and Art, Truth and Probability of Art, and The Gifted Man, by Hermann Türck, in two parts. And, it’s illustrated. The cover painting is by Gerard Wagner and an introduction by Rudolf Steiner.