Aristotle, and W. Rhys Roberts. Rhetoric. Mineola, NY: Dover, 2004. Kindle Electronic Edition.
Book I, chapter 15.
Aristotle identifies five “non-technical” means of persuasion . . . laws, witnesses, contracts, tortures, oaths” (Aristotle I.15, B 1375a). If a written law conflicts with the rhetorician’s desire, he normally makes an appeal to natural law, which never changes. Aristotle gives numerous examples from history and literature to demonstrate that nature itself shows what is right. Witnesses can be brought in, including written matter, case law, and people to testify either to the rhetor’s point of view or about the opponent (Aristotle I.15, B 1376a). Contracts may be considered more or less convincing (Aristotle I.15, B 1376b) It may be argued that a contract is either binding or not. Aristotle views examination by torture to be very weighty (Aristotle I.15, B 1376b) It is possible to affirm that under torture a witness may lie or that he was very truthful. The matter of oaths is likewise difficult as some people may refuse to swear an oath and some may swear falsely (Aristotle I.15, B 1377a).