Kandinsky points out [in his book On the Spiritual in Art] that Theosophy (in its true sense; not as it generally appears) is yet another expression of the same spiritual movement which we are now seeing in painting.
In 'De Nieuwe beelding in de Schilderkunst', Piet Mondriaan, 'De Stijl' No. 1, October 1917, p. 54