Our habit is to divide up our human world into 
     compartments of different sorts of ‘realities’: natural and 
     artificial, physical and moral, organic and juridical, for 
     instance.
          In a space-time, legitimately and perforce extended 
     to include the movements of the mind within us, the 
     frontiers between these pairs of opposites tend to vanish. 
     Is there after all such a great difference from the point of 
     view of the expansion of life between a vertebrate either 
     spreading its limbs like a bat or equipping them with 
     feathers, and an aviator soaring on wings with which he 
     has had the ingenuity to provide himself?

It may not be necessary to enlarge here on the role of the 
infinitesimal calculus as an extension of print technology. More 
neutral than the alphabet, calculus permits the translation or