Spirituality & mysticism
In older art, biblical scenes were the rule rather than the exception, and the Church was a major client for artists. In the late 19th century, another form of spirituality appeared in art. Spiritism, or the ability to speak to the dead, was accompanied by scientific discoveries of phenomena such as electromagnetic waves and x-rays. If you could communicate over long distances through telegraphy, why should it be impossible to talk to the spirit world.
Mysticism and occultism strongly influenced many of the most famous modernist artists. The birth of abstract art was inextricably linked to the spiritual ideas that flourished in Europe around 1900. The Bauhaus school, the flagship of modernism, was highly influenced by esoteric movements. Students were called apprentices and were initiated into the secrets of crafts by masters, like when the great cathedrals were built, or in the freemason lodges. Artists such as Kazimir Malevich, Piet Mondrian, Paul Klee, Hilma af Klint, Wassily Kandinsky, Joseph Beuys and Yves Klein belonged to esoteric circles such as the Rosicrucian Order, the Theosophical Society and the Anthroposophical Society.