1. Rationalities

In the modern and contemporary world, scientific rationality, based on experience and shaped by mathematics has taken the upper hand upon the current vision of rationality. Scientific discourse is taken as the prototype of rational discourse, while argumentation is seen as the instrument of reason as reasonableness in human affairs. This position has been strongly reasserted by Perelman & Olbrechts-Tyteca ([1958]), S. Persuade, convince; Persuasion.

Ordinary discourse in action embodies different kinds of rationalities.

Rationality as common sense — Rationality as common sense can be defined as the art of thinking complying with the rules and intuitions embodied in traditional logic and adapted to social necessities by rhetorical argumentation. As a scientific concept, this vision of rationality has been shaken to its foundations by the development of axiomatic thinking, as exemplified by non-Euclidian geometries or by the invention of the imaginary unit i, such as i² = −1. In human sciences, the Freudian invention of the unconscious and the development of studies on ideologies and social determinisms, have most certainly challenged the vision of a sovereign subject transparent to him/herself, consciously mastering his or her calculus, intentions, discourses and actions. This double crisis directly affects the classical vision of the rational well-intentioned rhetorical orator.

Rationality as adaptation of a conduct to a goal — Rationality as adaptation of conduct directed towards a goal covers all forms of action guided by a script, recipe or pre-established conventional plan. To make good custard, for example, it is more rational to pour the hot milk on the eggs than to put the eggs in the hot milk, so that the cream will be more homogeneous. This principle of rationality merges with the consistency requirement between conduct and objective. It is exploited by all forms of refutation revealing a contradiction in the opponent’s conceptions and actions S. Ad hominem; Consistency. Since it is human to pursue several objectives at the same time, the resulting practical rationality is perpetually destabilized.

Rationality as adaptation of a conduct to a goal is compatible with crime. The Marquis de Sade is an outstanding arguer. Hence the possibility of delirious and despotic rationalities serving equally perverse goals.

Rationality related to a domain — Rationality depends on domains. A given behavior (with or without a linguistic component) is said to be rational if it conforms to recognized practices in the relevant domain, technical field, scientific paradigm or tradition of thought, S. Rules.

Democratic rationality — Democratic rationality is a quality of societies and groups where information is accessible; where free and contradictory examination of socio-political positions and oppositions may develop with a view to effective decision-making; where there is a right of reply; and where the safety of the opponents is ensured. It is a form of society in which the holders of legal power and violence are brought to account for their use.

Is rationality  governed by rules? if one tries to express the preceding conditions as a set of rules, they will have to be hierarchized and context-sensitive in order to integrate various genres and practices.

2. Discursive and argumentative rationality

Language rationality — From a linguistic point of view, a discourse is deemed rational if it is well built, if it is understandable, if the speaker can account for it and if it makes sense in relation to the problem discussed or the task under way.

The reasonableness paradox created in an argumentative situation driven by a question is that each of the competing discourses taken in isolation makes sense, but, taken together, they become contradictory. To discriminate between these answers, theorists of argumentation need a criterion, which would be stronger than meaning, and, to that effect, introduce the notion of rational or reasonable discourse into their models. The different families of theories of argumentation can be related to different visions of rationality.

Discourse rationality and discourse types — Argumentative discourse is not the unique receptacle of discourse rationality. There is not one, but several discursive rationalities: argumentative rationality, narrative rationality, descriptive rationality, and so on. Irrationality is manifested in incoherent and delirious narrations, descriptions or prescriptions; any ill-conceived installation diagram which can be called irrational, because it is useless.

Rational discourse and effective rhetoric — Effective rhetoric, focused on the persuasion of an actual, relevant audience is a case of goal adaptive rationality. It is compatible with verbal and nonverbal manipulation.

Rational discourse as justified and rectified discourse — The definition of rational discourse as a justified discourse develops the idea that a discourse is reasonable insofar as its claim is not asserted on the basis of individual certainty, but openly supported by other propositions, exploiting some kind of public data connected to the claim by some recognized rule, albeit fragile. Its rationality increases if it exhibits its weak points, suggesting the directions that must be taken to improve it; as Bachelard says, there is no truth, only rectified errors. The Toulminian layout meets these requirements: the Claim is based on Data, according to a Warrant, itself supported by a Backing, and duly Qualified. The critical instance is represented by its trace, the Rebuttal, indicating the potential point of refutation.

The practice of dialogue, whether remote or face-to-face, can be considered to be the exercise of the critical function of language. A speech is more rational if it has been duly criticized, that is, if it has survived a number of contradictory encounters. Criticizing does not mean “denigrating” or “rejecting”, but “passing a judgment”, positive or negative, on an activity. The observation of the data shows that the partners involved in an argument spend much time evaluating their partner’s arguments (Finocchiaro 1994, p. 21). Argumentative speech is evaluated in a meta-discourse, produced under any conditions, face-to-face or at a distance in space and in time. Any approach to argumentative discourse concerned with empirical adequacy must take this critical dimension into account.

For the New Rhetoric, arguments are assessed by the participants in the rhetorical event; the rationality of an argument increases with the number and quality of the interested and competent audiences who accept it. The progression towards human rationality is seen as an evolution from a particular to a universal audience, S. Persuasion.

The dialogue models of argumentation put the critical activity at the center of their concerns. Pragma-Dialectic and Informal Logic develop a critique of argument based on the notion of fallacy. To detect fallacies, pragma-dialectics uses a system of rules, while informal logicians use the technique of critical questions. S. Paralogism; Sophism; Fallacy; Norm; Rules; Evaluation

3. Rational argumentation, as a “dream of language”

The Argumentation within Language theory of Anscombre and Ducrot and the Natural Logic of Grize make no commitment to rationality; they are not irrational but a-rational. Any discourse being argumentative, the idea of ​​rectifying a discourse in order to improve its argumentativity or its rationality does not make sense. These theories are just concerned with the fact that to be rational a discourse must first be meaningful, S. Schematization; Orientation.

The Argumentation within Language theory proposes a radical criticism of the capacity of discourse to achieve any kind of rationality. Conclusions are seen as mere semantic developments of the arguments, the argumentation process being driven by the linguistic orientations of the utterances; the discourse develops according to the orientations of natural language, which are denounced as biases by fallacies theories, in search of a referenced, neutral, objective language. Rephrased in the language of fallacies, this amounts to the claim that argumentation in natural language is circular, so fallacious. It results that argumentation as a rational process is a “dream of discourse” (Ducrot 1993, p. 234). Following this metaphor, the rational pretension of argument (as found in Perelman, for example) will be seen as a “rationalization of the dream”, and the criticism of the arguments, as a “criticism of the dream”, whereas dreams can only be exposed and interpreted as such. S. Demonstration.

4. Rationality and rationalization

Psychoanalysis uses the terms rationalization or intellectualization to refer to discursive constructions claimed to be rational by the subject who tries to account for his or her actions, representations, feelings, symptoms or delirium. Psychoanalysis objects to such reconstructions that the subject has no conscious intellectual access to their true source (Laplanche and Pontalis, 1967, art. [Rationalization]):

Whenever possible, [the ego] tries to remain in good terms with the id; it clothes the id‘s unconscious commands with its preconscious rationalizations […] In its position midway between the id and reality, it only too often yields to the temptation to become sycophantic, opportunist and lying, like a politician who sees the truth but wants to keep his place in popular favor. (Freud [1923], p. 55).

The expression counter-argumentation can be used to refer to any kind of discourse, argued refutation or objection, going openly against an argumentation. A mere “No!” can be considered as a counter-argumentative move, even a nonverbal expression of rejection clearly interpretable as such.

Unlike direct refutation, a specific “argumentation vs. counter-argumentation” situation occurs when the refutation is reciprocal and indirect:

— Speaker S1 argues for proposition M.
— Speaker S2 counter-argues for proposition R, incompatible with M:

S1 — Let’s built the new school here, the land is cheaper.
S2 — Let’s built the new school there, the students will waste less time commuting

S2 makes a counter-proposition R, providing an alternative to M.

Argumentation and counter-argumentation play a reciprocal role in refutation. In such a polarized situation, the fact of providing a reason for doing R, incompatible with M, serves as a reason for not doing M. Any good reason for supporting R is seen as a counter-argument to M.

The argumentation / counter-argumentation structure may correspond to an emerging argumentative situation, or to the moments when the participants present and argue their position without considering the antagonist’s proposal, which can occur at any time in a concrete argumentative situation.

An argued position can be presented in isolation in an autonomous text without refuting or even mentioning any existing counter-argumentation. Adopting such a strongly assertive strategy avoids the paradoxes of refutation, but can be seen as a kind of contempt for the argument put forward by an opposing party. S. Question; Contradiction; Antithesis; Dismissal.

As is the case with weak refutations, a weak counter-argumentation will reinforce the attacked position. In the following passage, Noam Chomsky considers that his opponent, the philosopher Hillary Putnam, has failed to develop a counter-argumentation, even a counter-proposal, and argues that this shows that he, Chomsky, must be right:

So far, in my view, not only [Putnam] has not justified his positions, but he has not been able to clarify what these positions are. The fact that even such an outstanding philosopher fails to do so, may allow us to conclude that…
Noam Chomsky, [Discussion on Putnam’s Comments], 1979.[1]

The praise of the opponent as an « exceptional philosopher » is a characteristically eulogistic and perfidious accompaniment to this kind of refutation:

By refuting you, I’m refuting not just any philosopher, but a Master – and therefore, a fortiori, all the philosophers who are opposed to my views.

S. Politeness; Ignorance; Paradoxes.

[1] Noam Chomsky, Discussion sur les Commentaires de Putnam. In Piattelli-Palmarini M. (ed.). Théorie du Langage, Théorie de l’Apprentissage. Paris: Le Seuil. 1979. P. 461.

According to H. P. Grice, the intelligibility of the conversation is ruled by “a rough general principle which participants will be expected (ceteris paribus) to observe”, namely:

‘Make your conversational contribution such as is required, at the stage at which it occurs, by the accepted purpose or direction of the talk exchange in which you are engaged’. One might label this the Cooperative Principle. (1975, p. 45; capitalized in the text).

This “Principle of Cooperation”, is specified under four forms, “Quantity, Quality, Relationship and Manner” (ibid.).

— Quantity: “I expect your contribution to be neither more nor less than is required” (ibid.).
— Quality: “I expect your contribution to be genuine and not spurious” (ibid.). This can be compared to the requirement of accuracy mentioned in the pragma-dialectical rule 8; the same concern is also found in Hedge’s Rule 1 “For an honorable controversy”, S. Rules.
— Relation: “I expect a partner’s contribution to be appropriate to immediate needs at each stage of the transaction” (ibid.). This concerns in particular the relevance of the turn in relation to the present topic of dialogue and action. Grice recognizes the difficulty of identifying what is relevant in an exchange. The pragma-dialectical “Relevance rule” deals with this same requirement (van Eemeren, Grootendorst (2004, p. 192). S. Relevance; Rules.
— Manner: “I expect a partner to make it clear what contribution he is making” (ibid.). This entry can cover the refusal of the obscurity of expression and action; of ambiguity (the first of the Aristotelian fallacies); of the unnecessary prolixity, corresponding to the fallacy of verbiage.

Grice holds that his principles capture the rational character of conversation:

One of my avowed aims is to see talking as a special case or variety of purposive, indeed rational behavior. (Id., p. 47)

as well as its reasonable character: Respecting these principles is not merely “something that all or most do IN FACT follow, but as something that it is REASONABLE for us to follow, that we should not abandon” (id., p. 48; capitalized in the text).

These four principles can be compared with those advanced by normative theories of argument, S. Rules.

A statement violating Grice’s principles is not eliminated as fallacious, but is understood as an indirect speech act. When a participant notes that something is not in conformity with a conversational rule, the reaction is not to accuse the partner of making an irrelevant or irrational contribution, but to engage in an interpretive process to identify why he or she has flouted the conversational rule. The analysis of fallacies reverts to this interpretive orientation whenever it adds to its logic pragmatic considerations taking into account the contextual conditions of the exchange.

In an argumentative situation, the concept of cooperation is a strategic issue redefined by the participants, who are not necessarily willing to cooperate, for example in their own refutation. There is nothing scandalous or irrational about this, insofar as partners are aware of being in such an intentionally opaque context, S. Politeness. Rational, reasonable, as well as honorable rules for discussion are intended to reintroduce or strengthen cooperation in such antagonistic contexts.

1. Logic

In logic, two propositions are converse (in a relation of conversion) if they swap their subjects and their predicates. “As are Bs” and “Bs are As” are converse propositions. The converse of a true proposition is not necessarily true, S. Proposition.

2. Grammar and argumentation

In grammar, conversion can apply to any binary structures. Restructuring an expression of the opponent, that is, playing with his or her words, can be instrumental in reversing the global orientation of his or her discourse, according to the mechanisms of the antimetabole, S. Orientation Reversal.

Well, you know, this talk about the so-called pleasures of retirement is just empty talk to mask the retirement of pleasures.
Personally, I’d prefer a frightful end to this endless fright.
González, on Kohl ‘He fought for a European Germany, never again a German Europe.” (El País, 07-01-2017)

One can radically counter-argue a proposition by emphatically supporting its converse, S. Causality (II); Analogy:

S1 —     A is the cause of B;
A is like B; A mimics, copies B.

S2 —     Not at all! B is the cause A!
B is like A; B copies A.

In the same way, a sweeping defense strategy consists in converting the roles of accuser and accused, first by applying the reciprocity principle, “it takes one to know one”:

You blame me (for X), I blame you (for Y)
You filed a complaint against me (for X), I file a complaint against you (for Y).

and, second, by converting the position about the same criminal offense:

You are the culprit, you did it, you, who accuse me!

The child’s reply “he who says it did it” converts the accusation, , and justifies the counter-accusation:

S1 — You stole the orange!
S2 — No, you stole it, who says it did it!

The fact that S1 accuses S2 is used by S2 as an argument to accuse S1. S. Reciprocity; Stasis.

The conclusion of an argumentation is usually expressed in a single statement, possibly expanded in a brief conclusive speech, S. Argument – Conclusion. The argument part, supporting and sometimes surrounding the conclusion, can be considerably developed along quite different lines, referred to as:

— Convergent argumentation, also called multiple argumentation, combines several co-oriented arguments, S. Convergence.

— Linked argumentation, also called coordinate argumentation is composed of several statements combining into an argument.

— Serial argumentation, also called subordinate argumentation is composed of a succession of argumentations, such as the conclusion of the first one is taken as argument to support a second one and so on, S. Sorite.

Convergence is a basic mode of organization of complex discourse supporting a conclusion, S. Convergent, Linked, Serial.
Two or more arguments are convergent when they independently support the same conclusion. The arguments are said to be convergent or co-oriented, and the argumentation is called convergent or multiple.
“Two reasons are better than one”: in a convergent argumentation, a claim is defended on the basis of several arguments which, considered separately, can be relatively inconclusive, but, considered as a whole, combine to make a stronger case: “My computer is beginning to age, there are discounts on the price of my favorite brand, I’ve just got a bonus, I will buy one! ”.

In the above diagram, each argument is represented as a whole. The following diagram spells out the transition laws according to Toulmin’s proposal, S. Layout; compare with linked argumentation:

As well as pro-arguments, counter-arguments can converge to refute a claim. S. Script.

This open structure defines the argumentative net, as opposed to the demonstrative chain. In the demonstrative chain, each step is necessary and sufficient; if one step is invalid, the constituent parts, and, in turn, the whole construction collapses. In the case of the argumentative net, if one link in the mesh breaks, the net can still be used to catch fish, at least the biggest ones.

In a convergent argumentation, the organization of the sequence of arguments is relevant. If the arguments are of a very different strength, a weak argument alongside a strong argument risks damaging the whole argumentation, especially if this argument ends the enumeration:

He’s a great hunter, he killed two deer, three wild boars and a rabbit.

In classical rhetoric, the theory of discourse general organization (Lat. dispositio) discussed the supposed different persuasive effects of the various possible textual arrangements of converging arguments of different strength, S. Rhetoric.

Convergent arguments can be merely listed (paratactic disposition):

Arg, Arg and Arg, so Concl

The argument can be connected by any listing or additive connective:

first, Arg1; second, Arg2; third, Arg3; so Concl.
Additionally, also, in addition, let alone, moreover, not only, 
besides

Connectives such as besides, not only, in addition, let alone, not to mention… not only add argument upon argument(s), they present them as if each one was actually sufficient for the conclusion, and are adduced just “for good measure” (Ducrot & al. 1980, pp. 193-232):

No, Peter will not come on Sunday, he has work, as usual, besides his car broke down.

The additive approach considers that each argument brings in a part of truth, and that these parts can be arithmetically added to create one big decisive discourse. Speech activity theory considers that by nature, an argument is presented as sufficient, and that their addition actually obeys the logic of commercial display for consumers (the audience), that is to say the speaker offers the audience a range of equally satisfying and self-sufficient arguments.

Case-by-case argument  — To refute the conclusion of a convergent argument, each of the arguments supporting this conclusion must be discarded. Thus, a convergent argument is countered by a case-by-case refutation, limited to cases that have been advanced by the proponent.

1. Definition

In logic, the square of oppositions links the affirmative and negative propositions, universal and particular, according to a set of immediate inferences, among them the relations of contradiction and contrariety, S. Proposition.

— Two propositions P and Q are contradictory when they cannot be simultaneously true or simultaneously false; that is, one of them is true, and the other is false, as shown in the truth-table below.
— Two propositions P and Q are contrary when they cannot be simultaneously true, but can be simultaneously false, S. Contrary and contradictory.

These terms can be easily mixed up. The easiest way to avoid confusion is to refer the relations of contrariety and contradiction to two kinds of universes, defining two kinds of opposites. Let U be a universe including a series of individuals.

(i) Contradictories — In the case of contradiction, the opposition is within a bi-dimensional universe, such as the traditional system of genre. “— is a man” and “— is a woman” are contradictory predicates in this system. In a non-traditional system of genres, they are contrary propositions.

U is a two dimensional universe; two properties P₁ and P₂ are defined upon this universe, such as:

— Any members of this universe possess either the property P₁ or the property P₂:
— None possess both properties P₁ and P₂: neither is both (P₁ & P₂). This is noted (P₁ W P₂), with the symbol ‘W’ for “disjunctive or”.

P₁ and P₂ are complementary properties; they divide the universe U into two complementary (non-overlapping) sets.
— P₁ and P₂ are contradictories (opposites); they are in a relation of contradiction.

(ii) Contraries — In the case of contrariety, the opposition is within a multi-dimensional universe such as the universe of colors. “— has white hair” and “— has red hair” are contrary predicates: one person cannot have both white and red hair (notwithstanding the case of badly dyed hair roots); and he or she may have brown hair.

U is a n-dimensional (more than two dimensions) universe: P₁ , … P_i, … P_n.

— Any members of this universe possess one of these properties, P_j; that is, is either a P₁ , … or a P_i, … or a P_n.
— None possess two or more properties P₁ , … P_i, … P_n, that is, none is both (P_k & P_l).
— P₁ , … P_i, … P_n are contraries; they are in a relation of contrariety.

To sum up, semantically connected predicates, or properties, are opposite if they divide exhaustively their universe of reference into a series of non-overlapping sets. If there are just two such properties, they are said to be contradictory properties; if there are more than two, they are said to be contrary properties. So, contradictories are the limit case of contraries.

2. Refutation by substitution of contrariety to contradiction

It follows that an assertion based on a contradiction can be refuted by showing that the universe under discussion should not be considered as two-dimensional, but multi-dimensional. This seems to be the case in the following example.

In 1864 Pope Pius IX published the Syllabus, that is, a collection or a catalog summarizing the positions of the Vatican about “modernist” ideas. Considered as retrograde, the Syllabus is strongly attacked by “the modernists”. In 1865, Mgr. Dupanloup, defended the Syllabus in the following terms; “they” refers to the modernists.
It is an elementary rule of interpretation that the condemnation of a proposal, condemned as false, erroneous and even heretical, does not necessarily imply the assertion of the contrary, that could be another mistake, but only its contradictory. The contradictory proposition is the one that simply excludes the condemned proposition. The contrary is the one that goes beyond the simple exclusion.
Well! It is this common rule that they apparently have not even suspected in the inconceivable interpretation of the Encyclical and the Syllabus they have been giving us for the past three weeks. The Pope condemns this proposition: “It is permitted to refuse obedience to legitimate princes” (Prop. 63).
They claim that, according to the Pope, disobedience is never permitted, and that it is always necessary to bend under the will of princes. This is jumping to the last end of the contrary, and attributing to the vicar of Jesus Christ, the most brutal despotism, and slavish obedience to all the whims of the kings. This is the extinction of the noblest of liberties, the holy freedom of souls. And that’s what they claim the Pope said!
Félix Dupanloup, Bishop of Orleans, [The September 15th Convention, and the December 8^th [1864] Encyclical], 1865[1].

Is the universe of the Encyclical binary or multidimensional? Let’s consider a position X.

— If it comes in a binary opposition, “allowed vs. forbidden”, then the proposals “it is permitted (to refuse obedience)” / “it is forbidden (to refuse obedience)” are contradictory contraries: only one of these propositions is true. If we condemn the proposition “it is permitted to refuse obedience to legitimate princes”, then we have to conclude that the contradictory is true, that is to say, “it is forbidden to refuse obedience to legitimate princes”, otherwise said: “we must always bow our heads under the will of the princes.”

Thus, for Dupanloup, the malevolent “modernists” substitute contradictories for contraries, what he describes as “jumping to the last end of the contrary”, which is a proper designation of the contradictories.

He accuses his opponents of reframing the Pope’s position, using a strategy of absurdification (an exaggeration up to the absurd, S Exaggeration.

— If the position X enters a three dimensional universe, as “prescribed / permitted (indifferent) / forbidden” then the proposals “it is allowed / it is forbidden” (to refuse obedience) are not contradictories but contraries: they are not simultaneously true, but they can be simultaneously false, e.g. if X is indifferent. The inference “If X is not fought, X is required” is not valid. If we condemn “it is permitted to refuse obedience to legitimate princes” then we can only conclude one or the other of these opposites:

It is prescribed to refuse obedience to legitimate princes.
It is forbidden to refuse obedience to legitimate princes.

As it would be difficult to admit that Pius IX, or anyone else, prescribes a systematic duty of disobedience to the legitimate rulers, we are left with the other member of the disjunction, that is, “X is forbidden.”

— If two or more additional options, “encouraged” and “discouraged” are introduced, we get a five dimensional universe “prescribed / advised / permitted (indifferent) / recommended / forbidden”. The interpretation “encouraged” is hardly possible, for reasons previously seen; “discouraged” could correspond to the intention of the Syllabus, such as interpreted by Dupanloup. One then wonders why this sentence seems so solemn : if we admit that something which is not recommended is something that we do not do without good reason, it is obvious that one does not disobey the legitimate prince without some good reason.

[1] Quoted after Félix Dupanloup, La Convention du 15 Septembre et l’Encyclique du 8 décembre [1864]. In Pius IX, Quanta Cura and the Syllabus. Paris: Pauvert, 1967. P. 104-105.

1. In dialogue, a contradiction emerges when a first speech turn is not ratified by the partner’s following turn. The contradiction is open when the two parties produce anti-oriented speech turns. When the opposition is thematized and ratified by both participants, it gives rise to an argumentative situation.

S. Disagreement; Argumentative Question; Stasis;
Denying; Refutation; Counter-argumentation.

Contradictions can be solved on the spot by a series of adjustments and arrangements, by playing on the margins of indeterminacy and windows of opportunity left by ordinary language and actions.

2. Non-Contradiction^@principle; Ad hominem; Consistency.

3. Contradiction as a relation between opposite terms, S. Opposites

4. Contradiction as a relation between propositions: S. Contrary and contradictory; Absurd.

The fundamental expression of argumentative coherence or consistency is non-contradiction.

S. Non-contradiction; Absurd; Ad hominem.

The consistency requirement is of special importance in systems of regulations of human behavior, religion, law, as well as ordinary institutional or familial rulings.

The consistency requirement is expressed a contrario in the refutation strategy mentioned in Aristotle’s Rhetoric, topic n° 22:

Another line of argument is to refute your opponent’s case by noting any contrast or contradiction of dates, acts or words that it anywhere displays. (1400a15; RR p. 373).

1. After the event as before

The topos ≠5, “On consideration of time” appeals to consistency. This topic is not explicitly stated, but presented through two examples:

If before doing the deed I had bargained that, if I did it, I should have a statue, you would have given me one. Will you not give me one now that I have done the deed? (Rhet, II, 23, 5; RR, p. 361).

The situation is this:

1. 1. X (asks nothing and) accomplishes a feat (maybe an impulsive heroic act)
   2. After this, he asks for a reward.
   3. Argument: if he had asked before, they would have agreed on a reward.

The hero considers that all feats must be paid for as such. It is as if the definition of the word feat includes the characteristic “deserves a reward”:

L1:   — If you do, you’ll receive…
L2:   — I have done and done well, so give me…

This topic explains the disappointment of one who reports the found wallet and receives no reward.

2. Human (in)consistency

Consistency may be the rule, but inconsistency is a fact of life. This is what topic n° 18 expresses:

Men do not always make the same choice on a later and on an earlier occasion, but reverse their previous choice. (Rhet, II, 23, 18; RR, p. 371)

This topic materializes in the following enthymeme:

When we were exiles, we fought in order to return; now we have returned, it would be strange to choose exile in order not to have to fight. (ibid.)

The enthymeme seems to assume the following situation. In the past, exiles fought to return home, and they returned; in the current situation, they are suspected of refusing to fight, and preferring exile. They deny the charge by this enthymeme, which is a claim of consistency, as in:

You fought for this position, now you can’t accept being thrown out like that!

This is a kind of positive ad hominem argument; it may presuppose an a fortiori: “We fought to return to our homeland, a fortiori we will fight to not be chased out of it!”
Those accusing them reply that “Men do not always make the same choice, etc.”

The opposing party argues from an opposing vision of human nature; the two opinions “men are constant / inconstant”, are equally probable (see ibid I, 2, 14; p. 25). They can thus be the basis for two antagonistic conclusions.

S. Ad hominem; A fortiori.

3. Consistency of the system of laws
and stability of the objects of the law

Lat. arg. a cohærentia, de cohærentia, “formation into a compact whole”.

3.1 Principle of coherence of laws, a cohærentia

This principle requires that, within a legal system, one norm cannot conflict with another; the system does not allow antinomies. An argumentative line can therefore be rejected if it leads to the view that two laws are contradictory; this is a form of argumentation from the absurd.

In practice, this principle excludes the possibility of the same case being settled in two different ways by the courts.

By applying this principle, if two laws contradict one another, they are said to do so only in appearance, and, as a consequence, they must be interpreted so as to eliminate the contradiction. If one of these laws is obscure, it must be clarified by reference to a less doubtful one.

The argument a cohærentia is used to solve conflicts of standards. To prevent this kind of conflict, the legal system provides for adages, which are interpretative meta-principles, such as “the most recent law takes precedence over the oldest”. These adages are interpretative meta-principles, coming from Roman law and sometimes expressed in Latin: “lex posterior derogat legi priori”.

3.2 Principle of stability of the object of the law, in pari materia

Lat. in pari materia: lat. par, “equal, like”; materia, “topic, subject” argument “in a similar case, on the same subject”.

The argument a cohærentia deals with the formal non-contradiction of laws in a legal system. The argument in pari materia, or argument “on the same subject”, expresses a substantial form of consistency. It requires that a law be understood in the context of other laws having the same goal or relating to the same subjects, that is to say the same beings (persons, things, acts) or the same topic.

The given definition of the subject of the law must be stable and consistent. The application of the argumentation a pari presupposes the stability of the legal categories. S. Classification; A pari.
This principle of consistency prompts the legislator to harmonize the system of laws on the same subject. What constitutes the same subject and the set of laws on the same subject might be questioned. Anti-terrorism laws, for example, are a package of different statutory provisions, for which it is necessary to ensure that the definition of “terrorism” remains the same in each of the passages that uses the term. If this is not the case, these laws need to be made consistent, which implies that they themselves must be underpinned by consistent policy.

The two topoi discussed in the two following paragraphs are taken from Aristotle’s Rhetoric. They are based on the two incompatible, but equally recognized substantial topoi, “human conduct is, or should be consistent” and “human conduct is inconsistent”.

4. Argument from narrative inconsistency

As a particular case of ad hominem argumentation, showing inconsistencies in the accusatory narrative can rebut a charge:

S1:    — you are the heir, you benefit from the crime, you killed to inherit!
S2:    — if so, I should have murdered the other legatees too.

The prosecution will have to prove that S2 also intended to murder the other heir, or otherwise find an alternative motive. The defense starts from the hypothesis put forward by the prosecution to show that the actions of the suspect do not fit in the proposed scenario; the accusatory narrative contains flaws or contradictions.

The argument of incoherent accusation exploits a basic principle of practical rationality: the actions of the suspect must be consistent with his or her claimed goal. The accused can refute the accusatory narrative by showing that, according to this narrative, he acted inconsistently:

You say I’m the murderer. But it has been proven that just before the crime, I spent an hour at the cafe in front of the victim’s home, everyone saw me. It is not coherent conduct on the part of a murderer to show himself at the scene of his crime.

Any weakness identified in the prosecution scenario can then be used to clear the defendant.

The principle of consistency of laws and the principle of stability of the subject of the law concern the coherence of the legal system. The argument from the inconsistency of the narrative exploits the resources of narrative rationality: all the narratives offered as excuses, all the narratives mingled with argumentation are vulnerable to this type of refutation.
Conversely, the argument seems plausible and reasonable because the story is so, and because the speaker knows how to tell it.

The strategies described in the topoi n° 22, 25 and 27 and probably 18 (cf. supra) of the Rhetoric are relevant to this discussion (Aristotle, Rhet., II, 23), S. Collections (2).

The word consequence can mean:

— Effect, referring to a causal, cause / effect relationship S. Causality.
— Consequent, referring to a logical, antecedent / consequent relationship, S. Connectives, §Implication

1. Effect-to-cause argumentation

The effect to cause argument goes back from the consequences to the cause. Given data is considered the effect of a hypothetical cause that can be reconstructed on the basis of this data combined with a known causal relationship between these type of facts and their cause. Other expressions can also be used, such as argument by the effect, or from the effect to the cause.

You have a temperature, so you have an infection

— Argument: A confirmed fact t, the patient’s temperature. This fact t belongs to the category of facts or events T, “having a temperature”, as defined by medicine. This is a categorization process.
— Causal Law: There is a causal law linking I facts “having an infection” to T facts, “having a temperature”
— Conclusion: t has a type T cause, an infection, and the patient should be treated accordingly.

This corresponds to the diagnostic process; one could speak of diagnostic reasoning.

The effect (the temperature) is the natural sign of the cause. Such natural, palpable, effects provide endless basis for argument by natural signs:

See! The cinders are still hot, there was a recent fire (… they cannot be very far)

In the area of ​​socio-political decision, the argument by the consequences corresponds to the pragmatic argument, transferring upon the measure itself the positive or negative evaluation of the effects of a proposed measure.
The pathetic argument scheme is a special kind of pragmatic argument.

The argument from the consequences is sometimes referred to in Latin as argumentation quia “because” in opposition to the arguments by the cause or propter quid “because of which”.
S. A priori, a posteriori.

2. Arguments by the identity of the consequences

The same kind of argumentation applies to deductions made from the implied meaning of words, as an appeal to the sense of semantic coherence or logical consecution:

Scheme: “Another topic consists in concluding the identity of precedents from the identity of results”
Instance: “There is as much impiety in asserting that the gods are born as in saying that they die; for either way the result is that at some time or other they did not exist” (Aristotle, Rhet. II, 23, 1399b5; F. p. 313-315).

If something is condemned because it forcibly involves mechanically something negative, then it automatically creates a category of causes “having that kind of negative consequences”, which must also be condemned. If the reason given for banning the consumption of marijuana is that it causes a loss of control, then all substances that cause a loss of control must also be banned, including for example alcohol.

3. Refutation by contradictory consequences

The refutation by contradictory consequences is a kind of ad hominem*, used in dialectic:

Peter says “S is P”.
S has the consequence Q: the fact is known and accepted by the opponent.
P and Q are incompatible
So Peter says incompatible things about S.

Example:

Pierre says that power is good.
Yet, everyone agrees that power corrupts (consequence)
Corruption is an evil.
The good is incompatible with the evil; to be good, power should exclude corruption.
Peter says contradictory things.