Generally received sayings also become common property owing to the very fact that they are anonymous, as, for instance, Friends are a treasure, or Conscience is as good as a thousand witnesses, or, to quote Cicero, Cato maj. iii 7. In the words of the old proverb, birds of a feather flock together. Sayings such as these would not have acquired immortality had they not carried conviction of their truth to all mankind.

Some include under this head the supernatural authority that is derived from oracles, as for instance the response asserting that Socrates was the wisest of mankind: indeed, they rank it above all other authorities. Such authority is rare, but may prove useful. It is employed by Cicero in his speech on the Replies of the Soothsayers de har. resp. passim. The soothsayers consulted as to the significance of certain prodigies had replied that they were due to the profanation of sacred rites. Clodius interpreted this as referring to the rebuilding of Cicero's house. Cicero argued against this in a speech to the senate (56 B.C.). and in the oration in which he denounced Catiline to the people, in Cat. III. ix. 21. when he points to the statue of Jupiter crowning a column, and again in the pro Ligario, vi. 19. where lie admits the cause of Caesar to be the better because the gods have decided in his favour. When such arguments are inherent in the case itself they are called supernatural evidence; when they are adduced from without they are styled supernatural arguments.

Sometimes, again, it may be possible to produce some saying or action of the judge, of our adversary or his advocate in order to prove our point. There have therefore been some writers who have regarded examples and the use of authorities of which I am speaking as belonging to inartificial proofs, on the ground that the orator does not discover them, but receives them readymade. But the point is of great importance.