“Bannister's mile remains a touchstone in the history of athletics not because Bannister set an unbreachable record - currently, the fastest mile is a good fifteen seconds under Bannister's. For generations, four minutes was thought to represent an intrinsic physiological limit, as if muscles could inherently not be made to move any faster or lungs breathe any deeper. What Bannister proved was that such notions about intrinsic boundaries are mythical. What he broke permanently was not a limit, but the idea of limits.” LimitsAnalogyRoger BannisterBannister S MileFour Minute MileIntrinsic Boundaries Book:The Emperor of All Maladies: A Biography of Cancer Source: The Emperor of All Maladies: A Biography of Cancer