2019/02/23

Tetravalent logic (Part 1)



Aristotle said: "Being is everything he knows", so that where there is real knowledge - not its appearance or shadow - knowledge and being are one and the same thing.
(R. Guénon, Mélanges, Chap. VI « Connais-toi toi même », 1976, Pp. 56)


All modern knowledge is based on logic. With a few rare exceptions - technical apparatus using fuzzy logic or states of quantum physics - all natural and human sciences (including Western philosophy since at least Plato) are based on classical logic, establishing the veracity or falsity of a proposal.

However, classical logic has limitations that have been known since its inception. These situations, which can be expressed in a few simple sentences, are negligently classified among the paradoxes.

The consequences of refusing to deal with these paradoxical situations are most critical, since this gap forces us to blindly focus on our understanding of the world and ourselves.

Since no one can ignore the fact that the modern world is going through an ultimate crisis, any contribution to broadening the scope of possibilities is welcome, and indeed, we might even say, necessary. This is the purpose of this article.

We will begin with a brief history of logic, going back before the appearance of classical logic, where we will see in passing that logic is born of metaphysics. This will lead us to an interposed dialogue between Heraclitus, Aristotle, Granger and Guénon.

We will then propose a formalization of a tetravalent logic with its truth tables, after having explained its necessity (part 2). We will end by applying the framework of this logic to the semantics of some attributes of the manifested and the unmanifested, where we will find each time the conceptions of Tradition (part 3).

It all starts with a negation

If we take a proposal P and its logical negation not(P) we can place ourselves in one of the following three cases:
  •     case 1: P is true or not(P) is true, exclusively;
  •     case 2: P and not(P) are both true, simultaneously;
  •     case 3: neither P nor not(P) are true, simultaneously.
Heraclitus of Ephesus (~541 - ~480 BC), descendant of the King of Athens and from a priestly family, proclaimed the unity and indivisibility of opposites, that is, the consideration of case 2, as evidenced by its Fragments:

    "All things are born according to the opposition... Change is an upward-descending road and the order of the world occurs according to this road..."

    "All things are mutually contrary. "

    "The god is day-night, winter-summer, war-peace, satiety-hunger. It changes like when you mix perfumes together; then you name it after their smell. "

    "What is cut in the opposite direction is assembled; from what is different is born the most beautiful harmony; everything becomes by discord. "

    "It is the disease that makes health pleasant and good, hunger satiety, fatigue and rest. "

    "What is contrary is useful; what struggles forms the most beautiful harmony; everything is done by discord. "

    "Join what is complete and what is not, what agrees and disagrees, what is in harmony and disagrees; of all things one and one, all things. "

    "They don't understand how what struggles with oneself can fit. The harmony of the world is in opposite tensions, as for the lyre and the bow. "

    "There is a hidden harmony, better than the apparent and where the god has mixed and deeply hidden differences and diversities. "

    "Death of fire, birth for air; death of air, birth for water. "

    "The same thing that lives and that which is dead, that which is awake and that which sleeps, that which is young and that which is old; for the change of one gives the other, and vice versa. "

The principle of non-contradiction rejects case 2: one cannot think P and non(P) true at the same time.

The principle of non-contradiction is an axiom, i.e. it is taken as a first truth that helps to demonstrate other theorems, but itself cannot be deduced or demonstrated. This is a relatively recent invention. It was popularized by Plato (428 - 348 BC) in La République (IV, 436b) and especially by Aristotle (~384 - ~322 BC): "It is impossible that the same attribute belongs and does not belong at the same time and in the same relationship to the same thing" (Metaphysics, Gamma Book, chapter 3, 1005 b 19-20).

The excluded middle was introduced by Aristotle as a consequence of the principle of non-contradiction.

The excluded middle (often wrongly described as a principle, because it is only a law) maintains that either a proposal is true or its negation is true. We cannot think the third hypothetical case, which is therefore rejected. [1]

It is essential to note that since ancient times the knowledge of truth and falsehood has been an experience of thought. The construction of logic derives from the knowledge of being, that is, of metaphysics.  (See in this regard G.G. Granger, Sciences et Réalité, Chap. De l’être au réel : le réel, concept moderne)

The combination of the principle of non-contradiction and the principle of the excluded middle have contributed to the foundation of the so-called classical formal mathematical logic.

In addition to its non-modal syllogistics, Aristotle developed a modal syllogistics in Book I of its Premiers Analytiques (ch. 8-22).

The first formal system of modal logic was developed by Avicenna, who proposed a theory of temporal modal syllogistics. Modal logic as a subject of study owes much to the writings of the Scholastics, in particular Guillaume of Ockham and  Jean Duns Scot, mainly for the analysis of assertions on the essence and the accident.

The "polyvalent logics" question the excluded middle since Lukasiewicz in 1910, which returns to the ancient question of "futurs contingents": if a proposal concerning the future could already be characterized in the present as true or false, we should admit that the course of events is determined in advance. Versatile logic challenges the principle of the excluded middle. They recognize values other than the true and the false, they admit modalities such as the possible, or, below that, the impossible (which is a reinforced false), and beyond the necessary (higher degree of the true).

Modal algebras developed since the 20th century provide models for the propositional calculation of modal logic in the same way that Boolean algebras are models for classical logic. [2]

There is now a whole spectra of intermediate logics, ranging from intuitionist to classical logic, depending in particular on the number of modalities (or truth values) and axioms chosen to constitute the logical system.

Which system is the most relevant to use to rebuild our knowledge, after binary logic?

Do sciences really make us discover the reality of things? Do they build the world from scratch in their laboratories, and then force us to believe it?

G.G. Granger, a professor at the Collège de France, argued that scientific reality was only a way of accessing a certain type of object:

    "Validation is first exercised by self-control of the application of operating rules, which are themselves formal objects of a logic. But what fundamentally distinguishes this self-control is precisely that it ultimately concerns not isolated elements of the logical-mathematical formal object, but the whole system. It is then characterized by the prefix "meta": it is no longer simply a question of reasoning at the level of logic or mathematics, but at a higher meta-mathematical level. A formal system is then tested in its total structure, in terms of its non-contradiction, completeness and fertility. The first criterion normally expected of its reality is certainly the establishment of its non-contradiction. But it has been understood since Tarski and Gödel during the century that has just ended that the establishment by meta-mathematical means of the independence of certain parts of the system, the truth of certain proposals at the same time as the impossibility of demonstrating them in the system, and even the impossibility of demonstrating at its own mathematical level the non-contradiction of the system, were also in a new sense the attributes of its reality...[.] We see therefore that in all cases scientific reality is necessarily dependent on a use of the conceptual imagination. " (Science et Réalité, Ed. Odile Jacob, 2001, Chap. 8 "Systèmes et réalité", Pp. 241-242)

We have stressed that the construction of logic derives from the knowledge of being, that is, from metaphysics. It is therefore mandatory to look at what Tradition has to offer in this regard. We use a capital letter T to indicate that we go back further than Aristotle and Plato. We started with Heraclitus, we continue in the footsteps of René Guénon, starting by explaining the importance of the ternaries.

After 2 there are 3, which give birth to 4

"What we have just said already determines the meaning of the Triad, at the same time as it shows the need to make a clear distinction between ternaries of different genres;[...]

One of these two genres is the one where the ternary is constituted by a first principle (at least in a relative sense) from which two opposite terms derive, or rather complementary terms, because, even where the opposition is in appearances and has its raison d'être at a certain level or in a certain domain, complementarism always responds to a deeper point of view, and therefore no longer truly in conformity with the real nature of what it is about; such a ternary can be represented by a triangle whose vertex is placed at the top (fig. 1).


The other genus is the one where the ternary is formed, as we said earlier, by two complementary terms and by their product or resultant, and it is to this genus that the Far Eastern Triad belongs; unlike the previous one, this ternary can be represented by a triangle whose base is on the contrary placed at the top (fig. 2).


If we compare these two triangles, the second one appears to be a reflection of the first, which indicates that, between the corresponding ternaries, there is an analogy in the true meaning of this word, i. e. to be applied in the opposite direction; and, indeed, if we start from the consideration of the two complementary terms, between which there is necessarily symmetry, we see that the ternary is completed in the first case by their principle, and in the second, on the contrary, by their resultant, so that the two complementary terms are respectively after and before the term which, being of a different order, is almost isolated from them. This is further clarified in both figures by the direction of the arrows, going, in the first, from the upper vertex to the bottom, and, in the second, from the bottom to the lower vertex;[...]; and it is obvious that, in any case, it is the consideration of this third term that gives the ternary as such its full meaning.

Now, what must be clearly understood before going any further is that there could only be "dualism" in any doctrine if two opposed or complementary terms (and then they would rather be conceived as opposed) were first posed and considered as ultimate and irreducible, without any derivation from a common principle, which obviously excludes the consideration of any ternary of the first kind; one could therefore only find in such a doctrine ternaries of the second kind[...]

The consideration of two ternaries like the ones we have just mentioned, having in common the two complementary principles of each other, leads us to some other important remarks: the two inverted triangles which represent them respectively can be considered as having the same base, and, if we figure them united by this common base, we see first that the set of the two ternaries forms a quaternary, since, two terms being the same in both, there are in all only four distinct terms, and then only the last term of this quaternary, located on the vertical line resulting from the first term and symmetrically to it with respect to the base, appears as a reflection of this first term, the reflection plane being represented by the base itself, i. e. being only the median plane where the two complementary terms resulting from the first term are located and producing the last one (fig. 3).


We have just seen that the two extreme terms of the quaternary, which are at the same time respectively the first term of the first ternary and the last of the second, are both, by their nature, intermediaries in a way between the other two, although for the opposite reason: in both cases, they unite and reconcile in themselves the elements of complementarism, but one as a principle, and the other as a result. »
(The Great Triad, 1946, Chap. II - Different kinds of ternaries)

René Guénon developed in more detail the meaning of the quaternary in Le Symbolisme de la croix (1931), which is entirely consistent with the above passage.


The square of Aristotle

In classical modal logic, four modalities are identified for evaluating a proposal:
  •     necessary (if and only if the proposal is not possibly false; "what cannot but be true");
  •    contingent (if and only if the proposal is not necessarily false and not necessarily true; "what may be false");
  •     possible (if and only if the proposal is not necessarily false; "what may be true");
  •     impossible (if and only if the proposition is not possibly true; "what cannot but be false").


« Another way of showing the relationships between the four modalities is to arrange them in a square configuration, which goes back at least to Aristotle. The square of the modalities is isomorphic to the logical square of the terms and to that of the form A (universal affirmative), E (universal negative), I (particular affirmative) and O (particular negative) proposals of Aristotelian logic (fig. 4).

Fig. 4
There are, in each of these squares, four fundamental types of relationships between their respective four terms: contradiction or negation (on the diagonals) contradiction or incompatibility (on the upper horizontal side) subordinacy or non-exclusive disjunction (on the lower side) subordination or implication (on the vertical sides). » (Lucien Scubla, L’aporie de Diodore Cronos et les paradoxes de la temporalité. Jean-Pierre Dupuy et la philosophie, 2007)

These 4 modalities are linked, only one is needed to define the other three. The interpretation in intuitive logic is as follows:
  •     impossible ≡ necessary that does not... not...;
  •     possible ≡ no impossible ≡ no need that does not... not
  •     contingent ≡ not necessary ≡ possible that not... not;
In this interpretation, the possible and the impossible derive from the necessary (or its negation). The quota also results from the necessary, but also from the possible (and therefore from the impossible). The modal square is thus only a reduced deformation of the primordial diamond as described by Guénon, which is constructed on equilateral triangles instead of isosceles rectangular triangles (Fig. 5). This reduction, an example of a progressive loss of meaning, is a special case whose generality has been perfectly explained by Guénon (cf. La crise du monde moderne, Le règne de la quantité et les signes des temps). [3]

Fig. 5

Let us note how much the conceptualization described by Guénon agrees with and extends G. G. Granger's conclusion :
« The reality of science objects would therefore, according to our analyses, mean a certain relationship between a virtual aspect and a current aspect of the representation of the experience. This would be the meaning of a unity of science, a unity that it would not be useful to simply designate as a "concordance" of the two aspects. It is therefore legitimate to use the plural to refer to scientific realities, insofar as, as we have tried to show, the thinking of science, in each of its fields, determines specific criteria for its achievement of reality. » (Sciences et réalité, Conclusion, Pp. 243)

This essay is extended by the formal propositional calculation in tetravalent logic, detailed in the second part. 

__________________________

This article is a translation of the original article published in French.

[1] In classical binary logic, the excluded third theorem is derived from the principle of non-contradiction by introducing the relationship of equality or equivalence, the Boolean negation operator, by accepting the additional axioms:
  •     identity principle: P = P
  •     elimination of double negation: not(not(P)) = P
then by establishing the values of the truth tables of the operators NOT, AND and OR and by first demonstrating the equality not(A and B) = not(A) or not(B).

The principle of non-contradiction is the proposal "P and not (P) = FALSE".
implies the proposition: "not(P and not (P)) = TRUE"
implies the proposition:" not(P) or not (no (P)) = TRUE"
implies the proposition: "not(P) or P = TRUE"
implies that "P is TRUE" or "not(P) is TRUE"
so the proposal of the excluded middle is verified.


[2] Lewis founded modern modal logic in his 1910 Harvard thesis and in a series of articles published between 1912 and 1932, when his book Symbolic Logic, written in collaboration with Langford, was published.

The logicians Brouwer and
Heyting in 1930 criticized, in the name of "intuitionist logic", a certain type of reasoning held according to the principle of the excluded middle applied to finite sets. They believe that one has no logical right to infer the truth of a proposal from the falsity of its negation. Heyting does not say that the excluded middle principle is always wrong, but it limits its scope.

The mathematical structure of modal logic, i. e. Boolean algebras augmented by unary operations (often called modal algebras), began to emerge with McKinsey who showed in 1941 that Lewis' S2 and S4 systems were decidable.

[3] Why a representation in the form of a diamond and not a tetrahedron? The latter would place the Contingency and the areas of the Possible and the Impossible on the same level. It would "shorten" the distance between the Contingency and Necessity. There is no way to justify these assertions. On the contrary, we will see in the last part how useful it is to keep the diamond model.


2018/05/25

La Signature du Quaternaire (4ème édition)



L'essai La Signature du Quaternaire - Logique, sémantique et Tradition est la compilation des deux études sur la logique tétravalente précédemment publiées sur Conscience Sociale, suivie d'une troisième étude inédite portant sur la sémantique liée à l'utilisation d'une telle logique, dans les champs des sciences modernes et traditionnelles.

Cette étude permet de replacer l'ensemble des sciences modernes, parce qu'elles sont issues de la logique binaire, dans une position relative, spéciale, réduite. Elle montre que la logique quaternaire inclut toutes les possibilités de la logique binaire, mais va aussi au-delà. Les sciences modernes ne sont qu'une simplification outrancière des sciences traditionnelles, voire en sont une déviation. Tout cela est parfaitement cohérent avec la Tradition, mais aussi avec les outils rationnels de la logique moderne. Cette étude vise à ébaucher un pont entre ces deux perspectives, pour permettre aux scientistes et aux scientifiques (aux plus ouverts d'entre eux, bien qu'ils soient rares) de franchir un gouffre jusqu'ici volontairement ignoré, jusqu'à la spiritualité. De l'autre côté du pont, les pratiquants d'une voie ésotérique seront confortés, s'il en était besoin, par la cohérence d'ensemble du monde manifesté (y compris par les productions scientifiques modernes telle l'informatique ou la physique), c'est-à-dire par son unité.

La logique classique présente des limites connues depuis son origine. On range négligemment ces situations, pourtant exprimables en quelques phrases simples, parmi les paradoxes.
Les conséquences du refus de traiter ces situations paradoxales sont des plus critiques, puisque cette lacune nous oblige à plaquer des œillères sur notre compréhension du monde et de soi.
Plus personne ne pouvant ignorer que le monde moderne traverse une crise ultime, toute contribution visant à élargir le cadre des possibles est la bienvenue et même, pourrions-nous dire, est nécessaire. Ce livre propose pour la première fois la construction complète, pas à pas, de la logique tétravalente booléenne avec toutes ses tables de vérité et le calcul propositionnel des propriétés et des syllogismes, après en avoir expliqué le fondement métaphysique. Cette nouvelle logique englobe toutes les propriétés de la logique binaire classique. Dans les pas de René Guénon, l’auteur nous entraîne dans l’application du cadre de la logique tétravalente à la sémantique des attributs au cœur de multiples champs du savoir, où nous retrouverons à chaque fois les conceptions de la Tradition. Une nouvelle annexe établit un rapprochement avec l’alchimie intérieure (Neidan) Taoïste.

Docteur es sciences de l’université Paris-Sorbonne, Bruno Paul est le fondateur de Conscience Sociale. Ce producteur culturel autonome pratique la transdisciplinarité, croise les expertises de domaines différents pour faire naître de nouvelles perspectives. Ce livre est sa seconde étude guénonienne.

L'ouvrage numérique -désormais dans sa 4ème édition- est librement disponible sur ResearchGate et sur Archive.org aux formats PDF, ePub ou HTML5 (de 13 à 20 Mo selon le format ; 198 p.) .
  • le format ePub diffusé sur researchgate a été testé avec les lecteurs Calibre/windows et  Lithium/Android avec les options de pagination "vue format paysage" et "scrolling" ; ce format est déconseillé car il présente plusieurs défauts : absence des numéros de séquence dans les démonstrations de la partie 2, et absence des lignes d'entêtes et du tracé des bordures des tableaux de la troisième partie. De plus le contenu de certaines lignes des tableaux est incomplet.
  • veuillez noter que sur le site archive.org les autres formats dont epub et mobi sont automatiquement générés à titre expérimental à partir d'une OCR ; leur fichier ePub en particulier est inutilisable en pratique.
Vous pouvez aussi acheter l'impression de la première édition, et ce faisant, soutenir l'auteur.

Cet ouvrage est diffusé sous licence libre CC BY SA. L'édition numérique comprend de nombreux liens dynamiques vers les documents de référence.
En même temps que le site Conscience Sociale, cet ouvrage a fait l'objet d'un dépôt légal.

L'empreinte SHA-256 du fichier PDF de la première édition numérique est la suivante : 
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L'empreinte SHA-256 du fichier PDF de la deuxième édition numérique est la suivante :
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L'empreinte SHA-256 du fichier PDF de la troisième édition numérique est la suivante :
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L'empreinte SHA-256 du fichier PDF de la quatrième édition numérique est la suivante :  
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Livre La signature du quaternaire

La première édition de ce livre a été recensée dans les Cahiers de l'Unité n°11, juillet-août- septembre 2018.

Deuxième édition avec Errata de la première édition : (19/05/2019)
Ayant pris connaissance d'éléments doctrinaux contenus dans d'autres travaux de René Guénon, des correctifs ont été apportés dans la troisième partie du livre. Des éléments ont été permutés entre les colonnes "doxa opposée" et "paradoxe", aux pages suivantes : 
  • p. 92, 96, 99, 128-132 : Correctifs prenant en compte le contenu de la lettre de René Guénon du 29 décembre 1937
  • p. 103-105, 114-119 : Correctifs prenant en compte une correspondance analogique indiquée dans l'article Le Zodiaque et les points cardinaux, É. T., (oct.-nov. 1945), republié dans Symboles de la science sacrée, chap XIII. (1962)

Troisième édition : (03/07/2019)
Apports à la deuxième partie : précisions à propos des formules z5, z6, z7.

Apports à la troisième partie :
  • restructuration des correspondances relatives à la Connaissance
  • permutation entre les doxas correspondantes à Mikael et Gabriel ; compléments sur les correspondances avec l’angélologie
  • réorganisation des correspondances relatives à la physico-chimie, pour les koua et pour les phases d’un projet
  • ajout des symboles hermétiques pour les règnes
  • ajout des correspondances pour les enseignes des jeux de cartes, pour les fêtes des saints et pour les phases de la manifestation universelle
  • précision importante concernant la correspondance avec les éléments
  • réorganisation du chapitre VI de la troisième partie avec la création de la section VI-1 et de nombreuses précisions sur les correspondances zodiacales pour les différentes ères
Apports à la conclusion : compléments

Quatrième édition : (13/08/2019)
Apports à la première partie :
  • ajout de correspondance avec les catégories d’existence issues du Commentaire de l’Échiquier des Gnostiques.
Apports à la troisième partie :
  • précisions sur le thème de la logique formelle
  • précision sur la « gravure au pélerin »
Ajout de l’annexe 3 sur l’alchimie intérieure Taoïste


Une nouvelle édition numérique du livre intégrant ces additions et correctifs a ainsi été préparée. Les liens de téléchargement sur cette page ont été mis à jour.

2017/12/15

Sophisme ou paradoxe du menteur ?


(image JP Petit, in Logotron)


L’expression la plus concise et la plus répandue du paradoxe du menteur est « je mens ». Ce dernier est connu depuis au moins le VIIe siècle avant J.-C. La difficulté consiste à déterminer si la phrase « je mens » est vraie ou fausse.
Le raisonnement courant est le suivant : 
  • Si « je mens » est vrai, alors je mens quand je dis « je mens », puisque je mens. Donc la vérité consiste à affirmer la proposition contradictoire : « je ne mens pas ». Donc la phrase « je mens », est fausse. Paradoxe.
  • De plus, si « je mens » est faux, alors je mens en disant « je mens », puisque cette phrase est fausse. Si je mens, alors il est vrai d’affirmer « je mens ». Paradoxe.

La première conséquence de ce paradoxe a été que les logiciens ont choisi depuis Aristote de refuser de prendre en compte dans leur système logique toutes les propositions auto-référentes, c’est-à-dire celles qui expriment une vérité à propos d’elles-mêmes.

On a admis que l’ambiguïté venait initialement du fait qu’il existait un seul terme en grec ancien pour exprimer « faux » et « mensonge ».

Pour autant, la logique formelle peut nous aider à démontrer qu’il n’y a pas dans ce cas de paradoxe logique. Il n’y a qu’un sophisme.

Reformulons l’expression du paradoxe pour la rendre sujette à moins d’interprétations : « la valeur de vérité de la présente phrase est FAUX ». Appelons q cette proposition.
Appelons p la proposition : « la présente phrase [existe] ».

La proposition q signifie que la valeur de vérité de la proposition p est FAUX, c’est-à-dire qu’elle exprime le fait que (p ↔ FAUX). Par définition, la proposition p est appelée une contradiction.

Par définition de q, nous pouvons écrire comme formule : q ↔ (p ↔ FAUX).

Quelle est la valeur de vérité de q ? Pour cela, raisonnons à partir de l’équivalence :
1. (p ↔ FAUX) 
2. (p ∧ FAUX) ∨ (¬FAUX ∧ ¬p)
3. FAUX ∨ ¬p
4. ¬p
Or (p ↔ FAUX), donc ¬p ↔ VRAI , pour tous p.
Donc la valeur de vérité de q est VRAI : il est vrai d’affirmer que p est une contradiction. 
En logique formelle, il n’y a pas ici de paradoxe.

Remarquons que la formule (p ↔ FAUX) , qui définit q, est équivalente à (¬p ↔ VRAI).
On peut donc écrire que la négation de « la présente phrase » est VRAI. La signification sémantique de cette négation n’est pas évidente à exprimer. On peut proposer pour ¬p, parmi d’autres expressions candidates : « la phrase que tu n’es pas en train de lire ».

Il est plus facile de rechercher la valeur de vérité portée par ¬q, c’est-à-dire par la formule :
1.  ¬(p ↔ FAUX) 
2.  ¬((p ∧ FAUX) ∨ (¬FAUX ∧ ¬p))
3.  ¬(FAUX ∨ (¬p))
4.   VRAI ∧ p
5.   p
Or (p ↔ FAUX), donc ¬q est FAUX. C’est cohérent avec q est VRAI.
Par définition, ¬q est donc une contradiction : la négation de l’affirmation que p est une contradiction, est une contradiction. Il est contradictoire de nier que p est une contradiction. 

(Note : nous avons utilisé ici les notations les plus courantes de la logique bivalente booléenne ; la démonstration et le résultat sont identiques en logique tétravalente.)