"O gracious Duke... let your reason serve to make the truth appear where it seems hid and the hide the false seems true."

     The character of Isabella

     in William Shakespeare's Measure for Measure

"Rhetoric may be defined as the faculty of observing in any given case the available means of persuasion.... If it be objected that one who uses such power of speech unjustly might do great harm, that is a charge which may be made against all good things except virtue."

      Aristotle, Rhetoric