Hindus following Advaita Vedanta consider "atman" within every living being to be the same as Vishnu or Shiva or Devi, or alternatively identical to the eternal metaphysical Absolute called "Brahman" in Hinduism.Michael McDowell and Nathan Brown (2009), World Religions, Penguin, , pages 208-210</ref> Such a philosophical system of Advaita or non-dualism as it developed in the Vedanta school of Hindu philosophy, especially as set out in the Upanishads and popularised by Adi Shankara in the 9th century has been influential on Hinduism.