The judge is in possession of the domain of justice, the witnesses, the domain of truth. The plaintiff uses overstatement for the purpose of amplifying the subject, and the defendant understatement in order to minimize it, unless perchance the dispute concerns praise or a demand for reward, in which case the order is reversed, and understatement is used by the plaintiff, overstatement by the defendant. . . The judge must be armed with the sceptre of justice, the plaintiff with the dagger of ill-will, the defendant with the shield of piety, and the witnesses with the trumpet of truth.A curious excerpt from Alcuin's Disputatio de rhetorica et de virtutibus, probably composed around 794 AD for his king (and student) Charlemagne. Most of the work, a handbook of forensic rhetoric, is a poor mishmash of Cicero and Julius Victor, but these three statements are strikingly original. The first abstracts two bodies in the courtroom, the judge and the witnesses, to two fundamental Forms, which do not necessarily overlap. Alcuin may be thinking of the classical distinction between fas (divine law), with truth and justice coextensive, and ius (human law), with truth and justice in apposition. The second statement introduces the two pleaders as mediators, intentionally falsifying, between these ideal spaces of truth and justice. The important irony in this proposition is that the truth resides in neither case: both, rather, are characterised by rhetorical presentations of the given subject, and it is emphasised that each account distorts the facts. This categorical separation of, and contrast between, truth and discourse suggests to the modern reader the speech-act theory of J. L. Austin which so interested Derrida and others. The third sentence symbolically reiterates this picture, syntactically posing plaintiff and defendant between judge and witnesses, and its iconography is martial: the sceptre pertains to the king, the trumpets to his messengers, with two soldiers competing in battle.
Alcuin's point is that it is the function of rhetoric to guide the court's motion from the stable Form of Truth (the witnesses) to that of Justice (the judge); or, to put it differently, to align the domain of justice with that of truth. The balance of pro and contra afforded by the two orators, neither 'true', is related to the Sceptical idea of equipollence, although in the courtroom, of course, a final decision must be reached.