Rudolf Steiner's contribution to humanity has been prodigious: farms, schools, clinics and laboratories have all been established on the spiritual philosophy he expounded. Hitler and the Nazis banned all his works. The Anthroposophical Society, established by Steiner in 1912, has adherents around the world. It is open to all creeds and colours, demands no endorsement of doctrine, and holds as a universal principle the striving for the knowledge of the spirit in man and the cosmos. In 'Knowledge of the Higher Worlds, and Its Attainment' Rudolf Steiner reveals - to those willing to undertake the necessary discipline - the method by which this 'knowledge of the spirit' may be obtained.