title_body: Is there a middle-written language?
upvoted_answer: The best possible approach to a writing system "from the middle" is probably a text spiralling outwards.
  
  One famous artefact, the Phaistos Disk, shows a spiral layout of the text, but is is unknown whether it should be read inwards (most scholars prefer this) or outwards and the writing system is still undeciphered.
  
  Your graphical samples suggest a symmetric progression of symbols to the right and left—I think this is unrealistic because lazyness and economy of writing will soon lead to the abandonment of one of the symmetric halves, leaving either right-to-left or -left-to-right writing.