Writing involves a couple of different metaphors; the main one is the correspondence of a written symbol with an oralsound. Another one is that a linear sequen

Writing involves a couple of different metaphors; the main one is the correspondence of a written symbol with an oralsound. Another one is that a linear sequence of glyphs matches a linear sequence of sounds. Obviously there are mechanical problems with fitting a long sequence of letters on a limited space. Boustephedron maintains the linear sequence of the letters by going back and forth. People quickly learned that it's much easier to read if you instead cut each line into segments and start each segment on one side of a page, but this breaks the visual metaphor of a continuous line of written symbols matching a continuous line of sounds. Inventing writing is really, really, really hard. Just as, given that we learned to read so long ago, it's hard to remember how hard it is to learn to read. Boustephedron is like training wheels for writing.