https://en.wikipedia.org/wiki/Thought-Forms

Thought-Forms: A Record of Clairvoyant Investigation is a theosophical book compiled by the members of the Theosophical Society A. Besant and C. W. Leadbeater. It was originally published in 1905 in London.[1][note 1] From the standpoint of Theosophy, it tells opinions regarding the visualization of thoughts, experiences, emotions and music. Drawings of the "thought-forms" were performed by John Varley Jr. (grandson of the painter John Varley), Prince, and McFarlane.