title_body: Are there any "unspeakable" languages? Sorry, my title is slightly misleading; what I'm after is more like a written language that doesn't have its roots in spoken language, and has no definitive translation into speech, but is none-the-less concise and clearly understandable. Tall order, I know - perhaps something similar would be cave-paintings: they seem to have a strong meaning that one could imagine was clear to people at the time, and which may convey a narrative of some sort; but the actual recital might have many variations. Or a more modern example: when you see a red circle around a drawing of a cigarette, with a red line across, you know it means that you are not allowed to smoke (so the meaning is clear and concise) - but the equivalent wording depends on the viewer, and could include phrases like "Don't smoke", "No smoking", or many others,
  
  It seems achievable, at least, that one could construct such a language, which might even be universally understandable; but has it already been done in the form of a full language?
upvoted_answer: The answer is a definite Yes, there are.
  
  The example that comes immediately to my mind is Bliss symbolics (also known as Semantography) by Charles Bliss from 1942–1949. As an additional bonus, it is still used and developped further, and may even be included into Unicode at some date.
  
  EDIT: The term to look for is pasigraphy. There were lots of pasigraphies (Blanke, Internationale Plansprachen, gives the number 60) mainly in the 19th century, but the most successful ones were created in the 20th century. There were both philosophical pasigraphies (often using digits or abstract symbols) and naturalistic ones (starting from pictograms).