Obituary - Carlo Dalla Pozza

The Italian philosopher Carlo Dalla Pozza (16-10-1942, 18-07-2014) was born in Taranto, in the Southern region Apulia, from Luigi Dalla Pozza, an officer of the Italian Navy from the region Veneto, and Cecilia Pontrelli from Apulia. During high school studies at the Liceo Scientifico Battaglini of Taranto, Giovanni De Tommaso, a tough old-style teacher of mathematics, gave him the taste for mathematical problems and for the elegance of proofs. Carlo studied literature and philology at the University of Bari, where he graduated with a thesis on Renato Serra under the supervision of Aldo Vallone. Throughout his life Carlo manifested his love for Italian literature, in particular for the 19th century poets Giacomo Leopardi, Giosuè Carducci (teacher of Serra) and Gabriele d'Annunzio. Among Italian classics he preferred Dante and Torquato Tasso. His post-graduate studies were in Linguistic Theory with Ferruccio Rossi Landi in Lecce and then at the Universitiy of Pisa, and in Logic and Formal Systems at the Catholic University of Milan.

Carlo Dalla Pozza worked for many years as a High School teacher in the province of Taranto, while he was scientifically very active, attending conferences and giving lectures in various occasions. Only around 1990 he obtained a permanent position at the University of Salento, Lecce, first as "tecnico laureato" and then as "ricercatore". A petition signed by Italian and foreign scholars asking that he should be promoted Associate Professor came too late in view of compulsory retirement policies in European academia.

Even as a high-school teacher Dalla Pozza had an intense research and teaching activity in Italian Universities. He taught master level courses in Logico-Mathematical Methods for Linguistics and Logic and Philosophy of Science from 1992 to 1995 and then also Philosophy and Theory of Languages from 2002 to 2011 at the University of Salento and continued to teach as "professore a contratto" after retirement until 2013. In 1996 after the death of Carlo's partner Cristina Galasso, Ruggero Ferro invited him at the University of Verona, where he taught Logic and Foundations of Computer Science for students of the humanities until 2002. Dalla Pozza had also several graduate students pursuing graduate studies or working towards a PhD in Italy and abroad.

Carlo Dalla Pozza had broad philosophical interests. A main influence on his philosophy of logic and languages were the works by Rudolf Carnap, with whom he shared the approach the logical analysis of language but also to probability theory. A main philosophical commitment of Dalla Pozza was to Alfred Tarski's theory of truth: for Dalla Pozza Tarski's analysis vindicates classical bivalence as a basic principle of logic and of the theory of meaning, if not directly an ontological principle. But Dalla Pozza's background in linguistics and in the works by John L. Austin (How to Do Things with Words) gave him the awareness of the pragmatic level as a fundamental component of language and the intuition that the controversy between classical and intuitionistic logic about the bivalence principle of truth could be resolved as an example of Quine's dictum that a change of logic can be explained by change of subject matter. The paper by Dalla Pozza and Garola A Pragmatic Interpretation of Intuitionistic Propositional logic is probably the most influential of Dalla Pozza's works. By interpreting with Michael Dummett intuitionism as a logic of the justification of assertive judgements they exhibit a domain where obviously bivalence does not apply but could be interpreted as a "pragmatic layer" of logic separated from the "semantic layer" of classical logic. In the pragmatic layer the sentential connectives of implication, conjunction and disjunction could be given an intuitionistic interpretation according to the Brouwer-Heyting-Kolmogorov interpretation. The modal S4 translation by Goedel, McKinsey and Tarski could also be regarded as a "projection" of pragmatics into the semantic layer, extended with Kripke's possible world semantics for modal logic.

Looking for an "intended interpretation" of Dalla Pozza's logical system,

we may say that its language is about types of correct linguistic utterances, endowed with an illocutionary force, and having a propositional content. In the picture of possible worlds or situation semantics, propositions classify situations and true propositions are facts; moreover the recognition of the truth of a proposition comes with factual evidence that provides precisely its justification. But what about utterances of expressions "A implies B" having the mood of an assertion?

What is their propositional content? Given the Brouwer-Heyting-Kolmogotov interpretation, "A implies B" is a type of justification functions transforming evidence for A into evidence for B. But for Dalla Pozza such a type cannot be a proposition, since it does not have a truth value in the classical sense: only its "semantic projection" in classical S4 is a proposition and does have a truth value in a possible world semantics.

But standard Kripke semantics for intuitionistic logic is not an adequate representation of intuitionism from an inuitionistic standpoint.

Lively philosophical discussions in particular at the University of Padua with the philosopher Enrico Martino led to question whether the representation of intuitionistic logic with Dalla Pozza and Garola's Logic for Pragmatics was acceptable from the principles of intuitionistic philosophy. The usage of a classical meta-theory, instead of an intuitionistic one, was justified as an instance of Occam's razor, but it can also be regarded as evidence of Dalla Pozza's commitment to the fundamental status of classical logic. Recent work shows that Dalla Pozza and Garola's framework can be easily given an intuitionistic interpretation once the Occam's razor policy is abandoned.

Dalla Pozza extended his Logic for Pragmatics programme with consideration of deontic logic and the logic of laws in the paper Una Logica Pragmatica per la Concezione Espressiva delle Norme (1997) his second main contribution. Distinguishing "expressive" and "descriptive" uses of the notion of moral and legal obligation, Dalla Pozza was able to use the intensional pragmatic level of his system for represent expressive uses of obligations and the semantic level, extended with the possible worked semantics of classical deontic logic KD, for descriptive uses of obligations. In general, the two-level structure of the logic for pragmatics gives a general scheme for the resolution of paradoxes concerning the use of classical logic in natural language representation (as in A Pragmatic Logic for the Expressive Conception of Norms and Values and The Frege-Geach Problem).

A new development of the work on deontic logic was developed in Dalla Pozza and Bellin A Pragmatic Interpretation of Substructural Logics, where the notion of "causal implication" was represented by the implication of Relevant Logic and the expressive notion of obligation was embedded in the framework of Linear and Relevant logics. It becomes then possible to represent formally inferences where the causal relation between statements A and B under frame conditions C allows one to infer the obligation of doing of B from the obligation of A. Kurt Ranalter's work and in particular his PhD thesis (see the paper A Semantic Analysis of a Logic for Pragmatics with Assertions, Obligations, and Causal Implication) provides an elegant proof-theoretic framework, modelled with the tools of category theory, for sophisticated applications of Dalla Pozza's work in this area.

Dalla Pozza's system of Logic for Pragmatics has also been extended to a logic of the justifications of assertions and hypotheses. Assuming a common sense duality between "asserting a proposition P" and "making the hypothesis that P may be false" (doubting about P), a pragmatic interpretation is given of a system of bi-intuitionistic logic, whose mathematical and computational properties have been studied (see G.Bellin, M.Carrara, D.Chiffi and A.Menti. Pragmatic and Dialogic Interpretations of Bi-Intuitionistic logic, Part I and II (2014),. To these themes Dalla Pozza indirectly responded with the forthcoming book on the demarcation problem which he worked to until the last days of his life. Here he used a model of learning by revision of the hypotheses based on Baysian probability theory.

A major competitor of Dalla Pozza's Logic for Pragmatics is Sergei Artemov's "Justification Logic", also presented in the 1990s and developed extensively since then. Carlo Dalla Pozza never attempted a comparison, leaving the task now to his friends and students.

Dalla Pozza was never interested in logical systems as mere mathematical structures, but rather as formalisms with an "intended interpretation", representing forms of reasoning occurring in science or in natural language, In fact his works always addressed major issues in the philosophy of science. With Giovanni Sambin he had lively public discussions on naturalistic interpretations of mathematics. His life long cooperation with the physicist Claudio Garola had in view the foundational problems of quantum mechanics, in the hope that the basic scheme of the logic for pragmatics could also be applied to reconcile conflicting viewpoints in the foundations of physics (see the early paper On the Logical Foundations of the Jauch-Piron Approach to Quantum Physics, 1988).

Similarly, his work on formal deontics and the logic of laws is a life-long interest from the participation to the "incontri di San Giuseppe" organised by Norberto Bobbio who introduced the analytic tradition of philosophy of laws on Italy, to the cooperation with Luigi Ferrajoli and his formal development of an axiomatic theory of constitutional democracy in his monumental book Principia Iuris. Dalla Pozza's commitment to liberal democracy and individual freedom had a progressive bent in his criticism of confusions between the principles of political liberalism and unbridled applications of free-market economy. But a fundamental attitude of aristocratic pessimism on the participation of masses to political life made him skeptical of Ferrajoli's belief in a progressive use of the notion of fundamental rights. Certainly his pessimism prevented him from becoming involved with political parties that in the 1960s and 1970s were still promoting democratic participation, as it was wished in the Italian Constitution of 1948.

Like other intellectual of his generation Carlo Dalla Pozza faced the problem of bringing scientific and analytic rationalism in an Italian culture deeply influenced by historicism in the great tradition of idealism of Benedetto Croce and Giovanni Gentile. Carlo took the task seriously by embracing a critically aware version of scientific rationalism. But he was still able to interpret philosophical choices as life choices rather than mere intellectual games.

His great warmth and contagious enthusiasm for life left a deep impression in all the people who encountered him and who eventually did not mind to have been slightly burnt by his flame. For Carlo did respect the freedom and the feelings of others, bringing in personal relations the same analytic attention he displayed in his philosophical work. Interestingly enough, an English speaker with intermediate knowledge of Italian confessed never having had any linguistic problem in conversation with Carlo, because of his capacity of attention and clarity of thinking.

A professional wrestler in his youth, Carlo Dalla Pozza practiced physical exercise throughout his life. In 2011 he refused extensive chemical and radiological therapies and only allowed two open brain surgeries without total anaesthesia, for the sake of retaining as much as possible his intellectual powers. In this way he was able to continue working until the last months of his life. He is survived by his partner Vera Vaglio Massa and lives in the memory of his friends.

(Gianluigi Bellin)