“Technical” and “Non-Technical” Evidence

1. The opposition “technical” / “non-technical”

Aristotle distinguishes between two instruments of persuasion, or rhetorical proof (pistis):

Of the modes of persuasion some belong strictly to the art of rhetoric and some do not. By the latter I mean such things as are not supplied by the speaker but are there at the outset — witnesses, evidence given under torture, written contracts, and so on. By the former I mean such as we can ourselves construct by means of the principle of rhetoric. (Rhet., I, 2; RR, p. 105)

Rhetoric is a technique, a “techne”, that is “a process that strives for perfection, occurring by means of the deliberate action of a human being” (Lausberg [1960] §1). That is why rhetorical proofs are called technical proofs (or artificial proofs), as opposed to non-rhetorical, or non-technical proofs (Lausberg [1960], § 351-426).

The distinction is made in relation to the judicial situation. “Technical” proofs are discursive, oratorical means of pressure.

“Non technical” proofs are proofs in the contemporary sense of the word. They correspond to the facts submitted to the court, the “given” material facts which the orator cannot manipulate, for example, the public declarations made by the witnesses, or the contracts signed between the two parties. The language of the contracts and the discourse of the witnesses is considered to be free from rhetoric, at least in their basic formulation, whilst the language of the orator is rhetorical, that is, endowed with an autonomous power of persuasion, if necessary, challenging material evidence, S. Pathos.


The technicaL vs. non-technical distinction bears on the three components of rhetorical action:

— Technical logos is defined by the use of topoi, signs, etc.; non-technical logos is defined by the parallel intervention of witnesses, contracts, etc.

— Technical ethos is a speech product, the self-made image of the orator embedded in discourse (Amossy 1999); non-technical ethos is the other-made image of the orator, something like his or her reputation, which can run counter to the first.

— The technical pathos is the strategic emotive communication, and the non-technical pathos corresponds to the spontaneous emotional communication, S. Emotion.

2. A now misleading terminology?

First and most importantly, this terminology is now opaque and counter-intuitive, incompatible with the contemporary use of the word “technical”.
“Non-technical” proofs are just proofs in the ordinary contemporary sense of the word.

All the elements called “non-technical” are the rough material submitted to the court. They may be practically sufficient to settle the issue definitively, yet, “[they] require, very frequently, to be supported or overthrown with the utmost force of eloquence” (Quintilian I. O., V, 2, 2). In other words, the speaker must interpret the testimonies, the content of the contract, the confessions, in order to transform this rough material into data, that is, to orient them towards a conclusion in favor of the party he represents. So, “non-technical proofs” are not free from language and rhetoric.

— The distinction is closely linked with judicial situations. Argumentation also deals with very different situations, such as, for example argumentation developing in everyday semi-technical discourse and presenting mixed kind of proofs. For these reasons, and to highlight terminological difficulties, in this book, the terms “technical” and “non-technical”, when used in their traditional rhetorical sense, are placed within quotation marks.

Such questions may seem somewhat irrelevant, but wrongly so. The opposition has a distinct structuralist nature, emotion, character, and situation being re-defined as discursive objects. This position has proven fruitful; nonetheless, it has its limits. The issue is the definition of the object of argumentation studies: should they be purely discursive data, and we shall then take into account only purely linguistic phenomenon, or contextualized interactional discourse, taking into account the situation and the ongoing collaborative actions?

3. “Non-technical” proofs

3.1 What are “non-technical” proofs

The “non-technical” evidence is the material, the factual elements, brought before the court. They define the issue structuring the debate, and may include elements such as, “witnesses, examinations, and like matters decide on the subject that is before the judges” (Quintilian, IO, V, 11, 44). They might receive a secondary rhetorical treatment, but their existence is beyond the reach of the rhetorician.

The list of non-technical evidence varies somewhat. Aristotle counts as non-technical, “witnesses, evidence given under torture, written contracts, and so on.” (Rhet, op. cit. supra). Quintilian counts as non-technical “precognitions, public reports, evidence extracted by torture, writings, oaths, and the testimony of witnesses, with which the greater part of forensic pleadings are wholly concerned”. (IO, V, 1, 2). Traditional lists include the following elements.

Precedent, authority, rumor

An important means of argument, appeal to authority, has sometimes been considered to be technical, sometimes to be non-technical. Different kinds of authority must be distinguished, and first, the authority of a judicial decision made by a judge recognized for his or her competence, and passed into judiciary custom; in other words, a precedent turned into a law. This is clearly a “given” of the judiciary situation, that is to say, a “non-technical” element. An authoritative statement can also be understood as (a declaration of) a socially recognized personality.

“Precognitions”, prejudices, rumors, public opinion is a form of authority, perhaps linked to the possibility of recourse to an appeal to the populus in Roman law, S. Ad populum.

Contract, written document

Whether or not a contract was signed is a fact, which may be decisive.

Material elements

Material elements, such as the murder weapon, or the bloody tunic of the victim, etc., all make up the judiciary hardware.


Oaths guarantee the citizen’s declaration.

Testimony, torture

Taking into account “reports” obtained under torture is shocking, and reminds us that the old democracies and republics put up with slavery and torture. The Rhetoric to Herennius presents the basic arguments about the use of such reports. The first argument advocates that they be considered in court, the second that they be discounted:

We shall speak in favor of the testimony given under torture when we show that it was in order to discover the truth that our ancestors wished investigations to make use of torture and the rack and that men are compelled by violent pain to tell all they know […] Against the testimony given under torture, we shall speak as follows: In the first place our ancestors wished inquisitions to be introduced only in connection with unambiguous matters, when the true statement in the inquisition could be recognized and the false reply refuted; for example, if they sought to learn in which place an object was put, or if there was in question something like that which could be seen, or be verified by means of footprints, or be perceived by some like sign. We then shall say that pain should not be relied upon, because one person is less exhausted by pain, or more resourceful in fabrication than another, and also because it is often possible to know or divine what the presiding justice wishes to hear, and the witness knows that when he has said this his pain will be at an end. (Ad Her., II, VII, 10)

The list of “non technical” proofs might be extended by elements such as the following:

— For some cultures or persuasion, miracles can create a form of non-technical persuasion.

— In the early Middle Ages, the trial by ordeal, or God’s judgment, was also believed to establish the truth in a non-technical way: if the accused is able to pass through the fire more or less alive, he or she is acquitted; if he or she dies, the punishment proves the guilt.

— In contemporary times, it would be necessary to add the forensic proofs, for example the DNA tests. All these proofs would be typically called technical, in contrast with rhetorical or language-based argument.

3.2 Superiority of non-technical evidence

In current cases, the facts, documents, witnesses or material evidence, make it possible to solve the problem and settle the dispute:

When one of the parties had “non-technical” evidence, the case was clear for the judges, and needed only a few words. (Vidal 2000, p. 56).

Factual evidence is clearly essential in the judiciary, language playing of course an important role for the presentation and orientation of facts. Evidence produced by rhetorical arguments is used only when factual evidence is missing, for lack of anything better.

“Non-technical” evidence is paramount in actual judiciary decision. “Technical” evidence comes to the fore in rather special cases, when any legal document, any physical evidence, testimony, etc. is lacking. Such an exceptional situation is staged in the comical anecdote where Tisias opposes Corax. Corax has agreed to teach Tisias his rhetorical skills, and to be paid according to the results obtained by his student. If Tisias wins his first trial, he will pay his master; if he loses, he will have nothing to pay. After completing his studies, Tisias sues his master, claiming that he, Tisias, owes nothing to him, Corax. Indeed, this is Tisias first trial, and either he wins or he loses. First hypothesis, he wins; following the judge’s verdict, he owes nothing to his master Corax. Second hypothesis, he loses; in virtue of their private agreement, he owes Corax nothing. How can Corax meet this challenge? He repeats verbatim Tisias’ pattern of argument but in reverse. First hypothesis therefore Tisias wins the case; by private agreement, Tisias must pay. Second hypothesis, Tisias loses the case; by law, Tisias must pay for the education received. In both cases, Tisias must pay. It is said that the judges kicked out the litigants.

Rhetorical proofs, operating in a language having no contact with the world, are proofs by default. This is a borderline case, not a prototypical case of the argumentative rhetorical use of language, which, in general, operates with elements of reality and conventions that constrain its unbridled use.