Quintilian (Marcus Fabus; 35CE -95CE) - How the orator should employ a lie

Quintillian was a Roman writer on rhetoric, and during the reign of the Emporor Domitian he was charged with the education of the Emporor's two great-nephews. It is with their training in eloquence that Quintillian concerns himseld in his Institutio Oratoria -  the most thorough treastment of an orator's education in classical literature. Here Quinttilian deals with how the orator may make the best use of falsehood. Politicians take note.

' Sometimes, too, we get a false statement of facts; these, as far as actual pleading is concerned, fall into two classes. In the first case the statement depends on external support; Publius Clodius, for instance, relied on his witnesses, when he stated that he was at Interamna on the nght when he committed abominable sacrilege at Rome. The other has to be supported by the speaker's native talent, and sometimes consists simply in an assumption of modesty, which is, I imagine, the reasonwhy it is called a gloss, while at other times it will be concerned with the question at issue. Whichever of these two forms we employ, we must take care, first that our fiction is within the bounds of possibility, secondly that it is consistent with the persons, data and places involved, and thirdly that it presents a character and a sequence that are not beyond belief: if possible, it should be connected with something that is admttedly true and should be supported by some argument that forms part of the actual case. For if we draw our fictions entirely from circumstances lying outside the case, the liberty which we have taken in resorting to falsehood will stand revealed. Above all we must see that we do not contradict ourselves, a slip which is far from rare on the part of spinners of fiction; for some things may put a more favourable complexion on portions of our case, and yet fail to agree as a whole. Further, what we say must not be at variance with the admitted truth. Even in the schools, if we desire a gloss, we must not look for it outside the facts laid down by our theme. In either case the orator should bear clearly in mind throughout his whole speech what the fiction is to which he has committed himself, since we are apt to forget our falsehoods, and there is no doubt about the truth of the proverb that a liar should have a good memory. But whereas, if the question turns on some act of our own, we must make one statement and stick to it, if it turns on an act committed by others, we may cast suspicion on a number of different points. In certain controversial themes of the schools, however, in which it is to be assumed that we have put a question and recieved no reply, we are at liberty to enumerate all the possible answers that might have been given. But we must remember only to invent such things as cannot be checked by evidence: I refer to occasions when we make our own minds speak (and we are the only persons who are in their secret) or put words in the mouth of the dead (for what they say is not liable to contradiction) or again in the mouth of someone whose interests are identical with our (for he will not contradict), or finally in the mouth of our opponent (for he will no be believed if he does not deny).'

Quintillian, The Institute, trans. H.E. Butler, Heinemann, 1921