Helena Petrovna Blavatsky (1831–1891) co-founded the Theosophical Society in 1875 and authored the major texts of the movement: Isis Unveiled (1877), The Secret Doctrine (1888), The Key to Theosophy (1889), and The Voice of the Silence (1889). She inspired many artists including Alexander Scriabin, Wassily Kandinsky, Piet Mondrian, Hilma af Klint, Nicholas Roerich, and Max Beckmann, and her thought played a decisive role for Rudolf Steiner, George Gurdjieff, and so many others that she has been called “the Mother of Modern Spirituality” and “the Mother of New Age.”