Inventor of Bell 47 helicopter.

Arthur's 7 stage theory of process illuminated Rudolf Steiner's 7 Post-Atlantean Epochs. Just as Arthur has a Turn at Stage 4 Level 4, so does Rudolf Steiner have the "Turning Point of Human History" the Event of Golgotha, death resurrection of Christ Jesus at the 4th stage (Graeco-Roman Epoch) at the 4th or deepest level of reality, the mineral earth.