Occult Science is one of the fundamental works of Rudolf Steiner, one of the greatest 'spiritual' critics of modern materialism. In it, he emphasises how the "conquest" of the world by "Science" has come at the expense of intuition and imagination: all that is hidden behind the physical universe has been lost and thought is driven to wander.behind the physical universe has been lost and thought is driven to wander in search of more stable supports than those provided by official 'science'.The 'spiritual' reality of the world has been rejected as superfluous, but man is able to recover the lost knowledge of the Spirit with a supreme effort of will.