• Are there personal testimonies?
  • What maxims or ancient wisdom applies?
  • What is assumed or supposed?
  • By what powers will you reason?
  • On what type of authority does the argument depend?
  • What law or rule applies to ____?
  • How recent are these statistics?  How was the data gathered?
  • Should we trust majority opinion on ____?
  • Is this universally true, or are there counter-examples? (Elenchus)
  • Who is a witness? ________
    • What is the testimony of the witness?
    • What did he see (event or character) to cause him to give this testimony?
    • Why does the witness think that?
    • If more than one witness, questions would be answered for each witness

Three Laws of Reason

A deductive or geometric certainty, also known as a demonstration, can be considered certainly true or certainly false, and therefore authoritative.  In this regard, Formal Logic provides authority.  This is the study of the Formal Logic of deduction.

Mathematical Certainty –

Number abstracted from things, and the concepts of quantity provide certainties and systems of certainty.  The grammar of multiplication tables or factors are complimented by the logic and laws applying to real and imaginary numbers.  Mathematics is traditionally assigned to the Quadrivium.


The Axiom, or common knowledge is the strongest of the intuitive proofs from testimony.   Axioms and Proverbs provide the grammar of common authority.

The authority, or ethos of the testifier determines the force of persuasion in this type of proof.

Probability -“There are three kinds of lies: lies, damned lies, and statistics.” – Mark Twain — or — Benjamin Disraeli

Inductive probability is more authoritative when it is more probable, and correspondingly less authoritative when it is less probable.  Complete induction, and therefore certainty, is impossible.  This probability offered as an argument is called a proof.  The Formal Logic of Induction is studied in Statistics.  Francis Bacon originates the rigorous focus on this Logic with the Novum Organum ( a reference to Aristotle’s Organon – a staple of  Formal Logic)

Mill’s Five Canons of the General Methods of Science

These laws apply to the science of observation and experiment for the testing of hypothesis.


Authority of possibility is governed by physical laws, and the laws of human conscience and prudence are authoritative concerning human choice, or ethics.