Italian Operational School

Italian Operational School (Italian: Scuola Operativa Italiana, German: Italienische Operative Schule; French: Ecole Opérationelle Italienne) is an interdisciplinary research group of independent Italian intellectuals founded in 1946 by Silvio Ceccato – until 1952 under the name “Italian Centre of Methodology and Language Analysis” – whose common interest consists in studying cognition and language in terms of operations. In 1947 the contributions of its members already enabled Ceccato to define and present “Operational Methodology,” the School’s foundation. Among the members of the first 10 years were Vittorio Somenzi (physicist), Giuseppe Vaccarino (chemist), Enzo Morpurgo (psychiatrist and psychologist), Ferruccio Rossi-Landi (philosopher, linguist), Giorgio Salvini (physicist), Antonio Borsellino (physicist), Adriano Buzzati Traverso (biologist, genetist), Paolo Filiasi Carcano (philosopher), Enrico Maretti (engineer) and Ernst von Glasersfeld (journalist). When Ceccato in 1957 founded the “Centro di Cibernetica e di Attività Linguistiche” (Center for Cybernetics and Linguistic Acivities) at the University of Milan and from 1959 began to work experimentally on machine translation and robotics, new members joined the group, among them Pino Parini (painter), Renzo Beltrame (engineer), Sergei Perschke and Jehane Barton Burns (linguists), Enrico Albani, Piero Pisani and Gian Piero Zarri (computer scientists) and Bruna Zonta (latinist).
In the first period (1947 to 1987) the group was chaired by Silvio Ceccato and had regular meetings mostly in Milan, Montecchio Maggiore and Vulcano in the private houses of Ceccato. During these 40 years the School progressively acquired new members and developed more and more into a current of thought based on Operational Methodology but with different streams within it (Somenzi 1987). The second period began in 1987 when the “Società di Cultura Metodologico-Operativa” was founded in Milan (with Felice Accame as chairman) for intensifying the collective dimension and promoting communication among the old and new members of the Italian Operational School.
^ History
The pre-history of the Italian Operational School begins with two turning points in the intellectual development of Silvio Ceccato, the “methodological turn” (1945) and the “operational turn” (1947), which together provided the basis for the development of “Operational Methodology.” Later, a “cybernetic turn” (1953) will complement these two early turning points and constitute with them a triad that best characterizes the essence of the IOS.
During the Fall of 1944 Silvio Ceccato was invited by Giuseppe Facchini to collaborate in a new scientific journal devoted to science critique called “Analysis” (Ceccato 1964a: 118) : he thus came in contact with a new circle of intellectuals – like Giulio Preti (philosopher), Livio Gratton (astronomer) and Adriano Buzzati Traverso (biologist) – and acquired from the meetings both a renewed confidence as well as a first glimpse of where to find his place in scientific inquiry: methodology. This “methodological turn” appears already in Ceccato’s first contribution to the journal (Ceccato 1945), which begins with a definition of methodology and presents a discussion of its consequences (Ceccato 1964a: 122).
During the following two years, Ceccato and his friends further developed their interest in methodology and began to apply the results of their investigations to linguistic analysis (Ceccato 1964a: 229 ff). In November 1946, Ceccato participates in Rome at the “Congresso Internazionale di Filosofia”; here he meets among others Ferdinand Gonseth “ (Ceccato 1964a: 201), Vittorio Somenzi and Giuseppe Vaccarino “ (Ceccato 1964a: 259), 3 persons who will have each a specific, important influence on his “operational turn” – i.e. the inclusion of an operational point of view into the foundation of his conception of scientific methodology (Ceccato 1964a: 135-141; Ceccato 1968: 176) – that characterizes Ceccato’s intellectual development in those years. This turning point had its focus in a “new fact” – as Ceccato calls it (Ceccato 1964a: 136), i.e., an insight into the relation between certain properties of things and what we do mentally.
The first explicit evidence of this operational turn appears in Ceccato’s work under the French term “Méthodologie Opérationelle” at a presentation entitled “Quelques Espèces d’Operations. Essai de Méthodologie Opérationelle” that he did in spring 1947 at the “Entretiens de Zürich,” organized by Gonseth (Ceccato 1964a: 261-301). This presentation of “Operational Methodology,” not only explains for the first time the School’s foundation but is also the first official mentioning of the School under the name “Italian Centre of Methodology and Language Analysis”; Ceccato means by that the interdisciplinary research group of Italian intellectuals who meet since 1946 and share with him the passion for the new methodology of studying cognition and language in terms of operations. The Italian term “metodologia operativa” appears for the first time in 1947 in the draft for a presentation entitled “Il nuovo convito, o dell’amore visto da un metodologo” (The New Convivium, or about Love in the View of a Methodologue) that Ceccato presented in a cultural salon in Milan in that year (Ceccato 1966: 96).
Later, in 1948, Ceccato devised the project of a systematic presentation of Operational Methodology, which would help some of his friends who were living far away (Somenzi in Rome, Vaccarino in Messina) in staying in touch with the development of the thinking of the Milan group (Ceccato 1966: 127). The project was never concluded, out of three planned parts only the first one was completed and published under the title “Teocono” (Ceccato 1949). Since Analysis had been unable to continue its publications, in 1949 Ceccato, with his friends of the “Italian Centre of Methodology and Language Analysis,” founded an own scientific journal also devoted to science critique and called “Methodos” (Ceccato 1966: 128). The first number contained the mentioned article called “Teocono” both in the Italian original version and in an English version translated by Ernst von Glasersfeld (Ceccato 1949). In this work Ceccato defines operational methodology and operational awareness as follows:
“Operational methodology is defined as ‘the path that leads to operational awareness’; and operational awareness is defined as ‘the result of the following operations: a) to invest something with the property of being the result of operations, …. b) to semantise the operata, the operations and the presences ….’” (Ceccato 1949, 55).
In 1949 Ceccato participated in the XXIII Congrès International de Philosophie des Sciences in Paris; in the introduction of his article he references the “Teocono” as published in Methodos, then in the first part he presents Operational Methodology (in French: méthodologie operative) and finally in the third part he applies it to education.
The term “operational school” appears for the first time in French, i.e. “École Opérationelle” in a presentation that Ceccato gave in 1951 in Paris at the local Philosophical Society and which was published in the society’s bulletin (Ceccato 1952b; Ceccato 1966, pp. 460-485). In the form “Italian Operational School,” the English equivalent extended with the adjective “Italian,” the term appears for the first time in 1952 in a famous article by Ceccato in which he presents the School as follows:
“This interest we have formulated in a program and in a procedure; and this has given rise to the Italian operational School which proposes to: ‘Indicate by means of agreed symbols, the provenience, i.e. the work and the material of a pro­duct equally indicated by means of agreed symbols” (Ceccato 1952c: 269).
Notice that here Ceccato clearly indicates a sequence: first came the formulation of the operational approach (program, procedure), then from here developed the school, as a group of intellectuals sharing interest in and contributing to develop and apply such an approach.
Towards the end of 1952 Ceccato moved to London in the hope to meet congenial researchers, have an early access to new developments in his fields of inquiry and find support for his research (Ceccato 1966, 585-648). It was here that in the Spring of 1953, towards the end of his staying, an event and an idea came to encourage Ceccato after a series of rather disappointing experiences (Ceccato 1966, 639) and became the starting point of what could be called the “cybernetic turn” in Ceccato’s thinking and in the activities of the Italian Operational School.
The idea had a keyword: Cybernetics. Vittorio Somenzi (see above), who had come to London for a meeting, introduced Ceccato to the field of “intelligent machines” and suggested him to visit Grey Walter, to read W. R. Ashby and Norbert Wiener. Ceccato was astonished and skeptical because he could not see from where the cyberneticists could have possibly taken the needed theoretical understanding of thought and language (Ceccato 1966, 639). But, at the same time he felt that the trend of research of the IOS would have something to offer for advancing research in Cybernetics. With the support of this renewed self-confidence he dared to ask for a meeting with Karl Popper, who in 1934 had published “Die Logik der Forschung” and was since 1949 professor of logic and scientific method at the University of London. When the meeting took place, Popper received Ceccato with “Come out with your problem!” in the tone of a doctor who tells his patient “show me your tongue!.” Ceccato presented the methodological-operational approach of the IOS and when Popper reacted with “Sorry, but I do not see your problem” he introduced the new idea, the construction of a machine which is able to talk and the related need to know the operations which enable it to do that. Popper remained skeptical: “In any case your machine would be a counterfeit,” he concluded (Ceccato 1966, 642-644). Despite this daunting encounter, Ceccato’s enthousiasm for Cybernetics remained strong enough: he saw in the machine which observes and describes an opportunity for the IOS to apply Operational Methodology and have in the working machine the demonstration of its validity (Ceccato 1966, 645). After Popper he met again Guido Calogero, at that time director of the Institute of Italian Culture in London, and was invited by him to give a talk. On May 28, 1953, under the title “The Italian Operational School,” Silvio Ceccato gave his first talk influenced by the “cybernetic turn,” beginning as follows:
“The Italian Operational School has lately been formed in order to realise a plan which comprises: a) A particular sort of operational analysis of thinking; b) The construction of an apparatus that thinks in the manner shown by the analysis. The first part of the plan is already far advanced in its realisation; the second part is still at the beginning.” (Ceccato 1966, 646)
In this way Ceccato became “the first in Europe to apply the cybernetic principle of self-organization to the domains of concept formation and language.” (Glasersfeld 1998).
^ Operational Methodology
As we can see in the previous historical background, Operational Methodology has been tightly linked to the Italian Operational School since its origin and can be considered as the School’s foundation. After more than a decade of further development of his operational approach, Ceccato, in his final report to a mechanical translation project based on Operational Methodology, in order to clearly define his approach, makes a few remarks about the reflections from which Operational Methodology originated:
“Put briefly, we had noticed that words like ‘part’, ‘whole’, and ‘rest’, ‘element’, or ‘composite’, etc. do not designate things of the observational kind, nor constitutive characteristics of them. Of a cup, for instance, we can say on the one hand ‘it is a part’ (of the service which, thus, becomes a whole) and on the other hand, without any change in its form, colour, etc., ‘it is a whole’ (in relation to the handle, the rim, and so on).
We therefore concluded that certain words do not designate anything observational, but designate, instead, operations which we carry out with regard to something else.
This was not entirely new. It was, in fact, rather banal, and it certainly would not have had far-reaching consequences, if we had not discovered (by asking which things one could consider to be constituted by these operations) that into this class we could also fit the things nominated by words like ‘general’, ‘concept’, ‘law’, and ‘particular’, ‘phenomenon’, and further ‘natural’ and ‘determinate’, ‘cause’ and ‘effect’, and finally also ‘subject’ and ‘object’, ‘reality’, ‘nature’, ‘world’, etc.” (Ceccato 1960, 22).
The following excerpt from Ceccato’s article “Teocono” (Ceccato 1949: 55) provides a good overview of the School’s understanding of its own foundation in the initial period and is particularly interesting because it also declares its two major sources of inspiration.
“Operational methodology is defined as ‘the path that leads to operational awareness’; and operational awareness is defined as ‘the result of the following operations: a) to invest something with the property of being the result of operations, by repeating an operation or operations, the result of which is this something (but neither is the number of operations limited nor the way of operating obligatory: the thing towards which one is operating, becomes invested with the property of being an operatum only by one’s beginning to operate; and only when the operating has ceased, when the last operation has been performed, has the thing, towards which one has been operating, become invested with the property of being presence); b) to semantise the operata, the operations and the presences; i.e. to give them names, so that words may accompany the operations’.
As operational methodology does not tend towards a definition (essence, concept, universal, idea, law), nor searches for an object, it has nothing to do with the theoretical-gnoseological or epistemological enquiries, nor with those of philosophy or science inasmuch as they are directed gnoseologically.
The direction that has been followed is partly original. As this trend can be considered an “operational view” (vedere in operazioni), precedents of it can be found in the works of Percy W. Bridgman (whose theoretical-gnoseological picture, however, has not been accepted) and in those of Hugo Dingler (whose proof of the necessary uniqueness of path has not been accepted either). Inasmutch a our direction abandons the gnoseological attitude as a ‘human adventure’, it is possible to trace an indirect continuation from actualistic Idealism; indirect, since idealistic theory of knowledge and epistemology, driven to exasperation after Kant (no longer continuously supported either by subject or by reality-truth) show already by the paucity of results that they have outlived their function (but from idealism, the definitely linear proceeding, among other things, has not been taken over).” “ (Ceccato 1949, 55).
In 1955 Ceccato participated in London at the Third London Symposium on Information Theory and presented there together with Enrico Maretti an extension of Operational Methodology, the first version of the so-called “correlational approach” to language. This approach had the task to enable the application of operational analysis to machine translation:
“In our opinion, linguists and engineers who have so far turned their attention to mechanical translation have been delayed by the lack of a workable description of the operations which men perform on translating. […] we believe that the research going on in the Italian Operational School will be of some use in this connexion. This research is carried on mainly with the view to constructing an apparatus which performs some of our mental operations and gives them verbal expression.” (Ceccato and Maretti 1956, 171).
The correlational approach distinguishes a correlative activity (correlating) which assigns a determinate temporal order to the results of mental operations and by that constitutes units of thought: “The things taken to constitute the smallest unit of thought are always at least three;” (Ceccato 1960, 36). These three elements are called ‘first correlatum’ (the first operand to enter the unit of thought), ‘correlator’ (the relating element) and ‘second correlatum’ (the second operand to enter the unit of thought).
A further major extension of the original approach arrived in the beginning of the 1960’: the so-called “discovery of attention” (Ceccato 1966: 20-23), which had been triggered by problems that had arisen working on the project of a machine that observes and describes events in its environment (Ceccato 1964). From then on, the basic assumption of operational methodology stated that the essential function (or activity) for the constitution of any mental content is the function of attention; as a consequence the operations that constitute mental contents need to be conceived as attentional operations (Bettoni 2007, 35-36).
^ Radical Constructivism
Operational Methodology and the Italian Operational School had a great influence on the development of Radical Constructivism so that the two currents of thought have become not only complementary but also similar. Many statements by von Glasersfeld demonstrate this, for example the following two; the first from the famous introduction to Radical Constructivism:
“Some of the many ideas I have taken over from Piaget as well as from Ceccato will be outlined … Piaget’s work has greatly influenced and encouraged me during the seventies, and before that the collaboration with Ceccato had provided direction and innumerable insights to my thinking.” (Glasersfeld 1984, 18); and the second from a paper on mathematical concepts:
“Like the methodology of Ceccato’s Italian operationalist school [IOS], radical constructivism is an attempt to do without the assumption of a priori categories or rules. Categories are seen as the result of mental construction …” (Glasersfeld 1992, 209).
The influence began in the summer of 1947 when Ernst von Glasersfeld was spending the summer in Val di Sogno on the Lake of Garda with his wife and little daughter. By a fortunate accident von Glasersfeld met there Silvio Ceccato (for details see: von Glasersfeld 2009, 126-128), a meeting that in his view “more than any other event, determined the future course of my life.” From that moment von Glasersfeld became a regular member of the IOS and participated in their informal meetings:
“During the following years, my apprenticeship in Ceccato’s group [the IOS], which met informally two or three times a year for a few days of intensive discussion, taught me to question all conventional ideas and the tacit assumptions in the traditional theories of knowledge.” (von Glasersfeld 1995, 7).
When Ceccato founded Methodos in 1949, von Glasersfeld translated “Il teocono” (Ceccato 1949) and other articles for the first issue and in the following years regularly translated Italian and German articles into English for the journal. But the period of his collaboration with Ceccato that most profoundly influenced his thinking and provided the basis for his later research when he moved to the USA was probably that of the last four years (1959- 1962). In this period Ceccato and his collaborators applied their operational analyses to two complementary experimental lines of research (Parini 2010): mechanical translation (Ceccato 1960) and the “cronista meccanico” (mechanical reporter), a machine that observes and describes events in its environment (Ceccato 1964).
In 1959 von Glasersfeld had become full-time research assistant at the ‘Centre for Cybernetics and Linguistic Activities’ that Ceccato had created at the University of Milan and worked on a machine translation project (Ceccato 1960) that was financed by the US Air Force. In this context von Glasersfeld became involved in the analysis of meaning:
“My first major task was to provide an analysis of the concepts that English and other languages, including Russian, express by means of prepositions (I had two native speakers of Russian to work with).” (Glasersfeld 1995, 8)
After the end of Ceccato’s project another US Air Force research office, with Rowena Swanson as project officer, financed a conceptual analysis project directed by von Glasersfeld: “In the following two years Piero Pisani, Jehane Barton, and I worked out a novel approach to the analysis of the meaning of sentences by computer (Glasersfeld and Barton Burns 1962).” (Glasersfeld 1995, 9). Since conceptual ana­lysis pertains to conceptual structures as tools that we use to organize and manage the flow of experience, this linguistic research can be considered as an early building brick of Radical Constructivism which shows how “Ceccato’s method for the analysis of meaning [Operational Methodology] came to play an important role in the development of the constructivist theory.” (von Glasersfeld 1995, 76).
The usefulness of the IOS approach to thought and language and its influence on von Glasersfeld research work clearly appears also later in the LANA project, for which von Glasersfeld created “Yerkish,” an artificial language for use by apes in computer-mediated communication (CMC) with machines and humans (Bettoni 2007). In defining Yerkes von Glasersfeld adopted the above mentioned “correlational approach” to language, which was based on the assumption that sentences express in language sequences (“correlations”) of mental operations performed at the cognitive level (Ceccato 1964b, 14).
Von Glasersfeld’s background in conceptual analysis allowed him to direct Michael Tomasello’s master’s thesis and dissertation, where he undertook the task of recording and analyzing all the linguistic manifestations of his daughter during the second year of her life: “It was an invaluable opportunity to see just how useful Ceccato’s approach to the construction of concepts that we had further developed and expanded in our computer procedures would be in the analysis of children’s conceptual development.” (Glasersfeld 1995, 12).
Von Glasersfeld was convinced that sooner or later conceptual analysis would have to deal with mathematical concepts. When in the mid-1970s he met Leslie Steffe, who ran a Piagetian research project in the Department of Mathematics Education at the University of Georgia, they at once discovered a vast area of agreement and began to collaborate in a research whose goal was to establish a viable model of children’s constructive activities in the context of arithmetic (Glasersfeld 1995, 15-18).
It was in this context that von Glasersfeld developed an attentional model of three basic concepts of arithmetic and mathematics: unit, plurality and number. The foundation of this model was the idea, first proposed by Silvio Ceccato (1966) “that the structure of certain abstract concepts could be interpreted as patterns of attention” (Glasersfeld 1995, 167).
As we see from the previous examples, the influence of the IOS on Radical Constructivism followed many paths over the different disciplines in which von Glasersfeld conducted his research:
“Radical constructivism arose from a variety of disorderly readings. It was an attempt to fit into a coherent model a number of ideas about knowing that had been disregarded by the philosophical mainstream. This effort would not have been successful had it not been for my early acquaintance with the work of Silvio Ceccato …” (Glasersfeld 2000, 3).
Despite the complementarity and similarity of the two currents of thought, Radical Constructivism was never accepted by Ceccato who was “always assuming that Ernst never removed himself from philosophy” (Accame 2007, 19). Besides Ceccato, also other members of the IOS, even those who are leading thinkers of its second period, like for instance Felice Accame, have serious doubts about the strength of Radical Constructivism:
“Ernst’s easy use of electively skeptical philosophers leads one to think that his pars destruens is not destruens enough to shift to the pars construens, without risking a fall.” (Accame 2007, 19).
^ Società di Cultura Metodologico-Operativa
The second period of the IOS began in 1987 when the “Società di Cultura Metodologico-Operativa” was founded in Milan, with Felice Accame as chairman. This Society considers itself as the continuation of the original Italian Operational School and wants to be an instrument for intensifying the collective dimension and promoting communication among the old and new members (Accame 2007, 22). Its aim consists in the dissemination and development of the theses of the Italian Operational School (see the presentation on the website, www.methodologia.it/presenta.htm). Between 1987 and 1997 the Society published a new journal called “Methodologia” conceived as the inheritance of Methodos. Another initiative of the Society have been two series of publications in Operational Methodology: the first series called “Metope” with 4 monographs published from 1988 to 1991 and the second called “Quaderni di Methodologia” with 9 monographs published from 1996 to 2001. Since 1989 the members of the Society exchange their views and share drafts of their work through a newsletter called “Working Papers” whose numbers are all freely accessible in pdf format through the website (www.methodologia.it/wp.htm).
^ Publication history
  • Version 1: Marco Bettoni, 8 July 2019
  • Version 2: Marco Bettoni, 18 September 2020
^ References
(B2007)  Bettoni M. (2007) The Yerkish language. From operational methodology to chimpanzee communication. Constructivist Foundations 2(2–3): 32–28. https://constructivist.info/2/2-3/032
(C1945)  Ceccato S. (1945) Su alcune conseguenze pragmaticali di una definizione. Analysis, 2, Edizioni d’Arte e Scinza, Milano.
(C1949)  Ceccato S. (1949) Il Teocono o “della via che porta alla verità. ” Methodos, I 1: 34–54; English translation by von Glasersfeld E. : Teocono or “Of the Path that leads to Truth,” 55–69.
(C1952a)  Ceccato S. (1952a) Une conscience operative comme base de l’enseignement en général et scientifique en particulier, XXIII Congrès International de Philosophie des Sciences: Pédagogie des Sciences, Paris 1949, Hermann & Cìe Editeurs, Paris. (1952) pp. 9–19.
(C1952b)  Ceccato S. (1952b) L’école opérationelle et la rupture de la tradition cognitive. Bulletin de la Societé Française de Philosophie, Mars-Mai 1952–1953, Armand Colin, Paris.
(C1952c)  Ceccato S. (1952c) Contra Dingler, Pro Dingler. Methodos IV: 15–16, 223–265; English translation by von Glasersfeld E. : Contra Dingler, Pro Dingler, 266–290.
(C1960)  Ceccato S. (1960) Linguistic analysis and programming for mechanical translation. Tech-nical Report No. RADC-TR-60–18. Gordon & Breach, New York.
(C1964a)  Ceccato S. (1964a) Un Tecnico fra i Filosofi: Come filosofare, Vol. I. Marsilio, Padova.
(C1964b)  Ceccato S. (1964b) A model of the mind. Methodos 16: 3–78.
(C1966)  Ceccato S. (1966) Un Tecnico fra i Filosofi: Come non filosofare, Vol. II. Marsilio, Pa-dova.
(C1969)  Ceccato S. (ed.) (1969) Corso di linguistica operativa, Longanesi, Milano.
(CM1956)  Ceccato S. & Maretti E. (1956) Suggestions for Mechanical Translation. In: C. Cherry (ed.) Information Theory. Papers read at a symposium on information theory held at the Royal Institution, London, September 12th to 16th. (1955) Butterworths Scientific Publ., London, 171‐180.
(G1984)  Glasersfeld E. von (1984) An introduction to radical constructivism. In: Watzlawick P. (ed.) The invented reality. New York: Norton 1984: 17–40. https://cepa.info/1279
(G1992)  Glasersfeld E. von (1992) A constructivist approach to experiential foundations of mathematical concepts. In: Hills S. (ed.) History and philosophy of science in science education. Queen’s University, Kingston: 551–571. https://cepa.info/1433
(G1995)  Glasersfeld E. von (1995) Radical constructivism: A way of knowing and learning. Falmer Press, London. https://cepa.info/1462
(G1997)  Glasersfeld E. von (1997) In Memory of a Pioneer, Silvio Ceccato, 1914–1997. Methodologia Working Papers 91. https://cepa.info/1489
(G2000)  Glasersfeld E. von (2000) Problems of constructivism. In: L. P. Steffe & P. W. Thomp-son (eds.) Radical constructivism in action – Building on the pioneering work of Ernst von Glasersfeld. London: Routledge/Falmer: 1–9. https://cepa.info/1520
(G2009)  Glasersfeld E. von (2009) Partial memories. Sketches from an improbable life. Imprint Academic, Exeter.
(GBB1962)  Glasersfeld E. von & Barton Burns J. (1962) First draft of an English input procedure for mechanical translation. Methodos 14(54): 47–79. https://cepa.info/1295
(P2010)  Parini P. (2010) Ernst von Glasersfeld and the Italian Operational School: Didactic Implications of Operational Awareness. Constructivist Foundations 6(2): 140–149. http://constructivist.info/6/2/140
(S1987)  Somenzi V. (1987) The Italian Operative School. Methodologia 1: 59–66.
Related publications (3)

Accame F. (2007) Ernst von Glasersfeld and the Italian Operative School. Constructivist Foundations 2(2-3): 18–24. https://cepa.info/23

Beltrame R. (2007) The Theoretical Environment around 1965. Constructivist Foundations 2(2-3): 25–28. https://cepa.info/24

Braffort P. (2007) Ernst Glasersfeld’s First Scientific Paper. Constructivist Foundations 2(2-3): 12–17. https://cepa.info/22