Institutio Oratoria

If Demosthenes or Cicero had spoken the words as they wrote them, would either have spoken ill And is our acquaintance with either of those two great orators based on anything save their writings? Did they speak better, then, or worse than they wrote? If they spoke worse, all that can be said is that they should have spoken as they wrote, while, if they spoke better, they should have written as they spoke.