THREE QUESTIONS TO ANDRES BOBENRIETH

1) When and how did you first hear about paraconsistent logic and start your work?
When I was a student of philosophy at the Universidad de los Andes in Bogotá in 1992 the lecturer in the first course in logic mentioned paraconsistent logic in passing. In the Master in Philosophy, at the Universidad Nacional de Colombia, I took a course with the anthropologist Guillermo Páramo (a very prominent academic in Colombia) who taught us about myths and their inherent inconsistencies, and presented with some rigor the basic elements of paraconsistent logic. At that time my father happened to be working in Brazil, so that, during the next holidays, I arranged a trip to Campinas to go to UNICAMP, where I went to the CLE and was very kindly received by Ítala D'Ottaviano and Walter Carnielli. They introduced me to the universe of paraconsistent logic and showed me many texts in the CLE library, so I was able to get a lot of photocopies. Ítala especially insisted that I should go to São Paulo to visit Professor Newton da Costa and put me in contact with him. A few weeks later I went to visit him at USP; he received me very kindly and we talked for a whole morning. All this changed my academic orientation and I decided to do my Master's thesis on paraconsistent logic. There were two reasons that determined my decision: 1) as an undergraduate I had done final degree work on Hegel, where the study of the notion of contradiction in his youthful writings had been central, 2) paraconsistent logic was a logical and also a philosophical development where several Latin American authors, starting with Newton da Costa, had played a dominant role (it is important to highlight this because there are Anglo-Saxon authors who tend to forget or hide it). Back in Bogotá, I began to read the first texts in which the different systems of paraconsistent logic were articulated, as well as more general reflections on inconsistencies (paraconsistency). It was a difficult process because there were very few general texts that could serve as introductions to the abundance of articles. I was particularly interested in the issue of how paraconsistent logic affects the conception of rationality, given that since Aristotle –clearly– but also before with Plato and Parmenides, it had been postulated that avoiding contradictions and/or inconsistencies was a minimum requirement of rationality. I kept on gathering information trying to understand it and I began to write about it, with the support of my Master’s supervisor, Professor Carlos Eduardo Vasco, who knew little about paraconsistency but a lot about mathematics and logic. What resulted was a master´s thesis of 500 pages, which in some sense was the text that I would have wanted to have at my disposal to introduce me to this whole logical-formal and conceptual universe. A very special opportunity for me was that Professor Clara Helena Sánchez invited Newton da Costa and Walter Carnielli to teach courses at the Universidad Nacional de Colombia. That allowed me to talk with Newton da Costa practically every day for a month. At the time that my master´s thesis was approved, the Colombian government had created the National Culture Prizes, and the way to enter was to send a text under a pseudonym, for which master and doctoral theses that had reached the highest academic marks were allowed to participate. Professor Bernardo Correa strongly encouraged me to apply. To the surprise of many, starting with myself, I won the National Philosophy Prize of Colombia in 1995, which led to the transformation of the thesis into a book that was published with the title (translated into English): Inconsistencies ¿Why not? A philosophical study on paraconsistent logic (Bogotá: Colcultura, 1996). (I should like to point out that I still think that the subtitle that the thesis had was better: "Philosophical traces in the path of paraconsistent logic", but the editors considered that the other was more explanatory.)

2) How did you further develop your work on paraconsistent logic?
Just before winning that prize I had returned to Chile, my country of origin, in which I had lived very little, and I started my academic career at the University of Valparaíso, where I still work. There I continued working on issues related to inconsistencies and their relation to rationality. I participated in the first two world congresses of paraconsistency (in Ghent and at Juquehy Beach in São Paulo state) and there I met and interacted with the main researchers in the area. I went to do my PhD with Professor Steven French at the University of Leeds, for which I had a grant from the British government and from the university. There I had the opportunity to interact every day with Steven and also with Otávio Bueno as well as with other leading researchers. It was a very remarkable experience in many senses. It enabled me to know better how philosophical work is carried out in some prominent places in the English speaking countries. My dissertation title was: Inconsistencies and their rational tracks (University of Leeds, 2003). It tried to deepen philosophical reflection about inconsistencies, and not only to defend a paraconsistent position, which it does, but also to inquire why consistency remains a prevailing desideratum of rationality. I do not think that it is enough to say that it is so because of an "Aristotelian indoctrination", or because people have a conservative view and/or a received defense of classical logical principles. I think it has a philosophical substrate that dwells within human conceptual praxis. Since then I have published articles on historical and philosophical aspects of some logical developments about inconsistencies, as well as the conceptual distinctions that can be made in a series of phenomena or situations that usually are, in a simplistic way, put together in a big bag labeled contradictions and/or inconsistencies. By the way, I have defended the view that these terms are not entirely equivalent and that contradictions should be considered as a proper subset of inconsistencies.

Andrés Bobenrieth with Alessio Moretti
3rd World Congress on the Square of Opposition
American University of Beirut, Lebanon, 2012
The Many Faces of Inconsistency

3) How do you see the evolution of paraconsistent logic? What are the future challenges?
A lot could be said about this, but I will focus on a few specific aspects. When I began to investigate these issues, it was said that the study of paraconsistent logic was just beginning and that there were many things to do and that they could shake logical and philosophical thinking. It has been more than 25 years in which an enormous amount has been written on the subject, but I have the impression that the predicted tremor has not been felt so much. The reasons for this may be many, starting with its perhaps being still too early to affect 25 centuries –at least– of a very established tradition of defending consistency, but my impression is that, except for those who have worked in paraconsistent logic and paraconsistency (which I think are not the same, although obviously they are related), the option of accepting explicitly and openly inconsistencies does not go beyond being a "curious" or even "interesting" option, and has never really taken very seriously or in depth. Considering that this interview will be read mainly by people working in paraconsistency, I am going to make a controversial statement: in my opinion the defense of dialetheism has done no favors to the paraconsistency outlook, because it has become an extreme position that is attacked by many, generally distortedly, and has ended up suppressing a more substantive discussion about the best way to deal with inconsistencies. In the Anglo-Saxon philosophical world, I have many times seen it pointed out as a possible position on various issues, but it ends up being a cliché to say that that "crazy idea" remains an extreme position. In fact I heard Kripke (in Oxford in 2001) refer to it and then disqualify it immediately by saying "I do not read such things". On the other hand, I do not see that much has been contributed by the reiterated affirmation that "there are true contradictions", the liar sentence (and its variants) being the foremost paradigmatic example. In my opinion, it is much more interesting to reflect and work on the theoretical and practical options that are located in the interval that has at its endpoints the classical and the dialetheist positions. The question should not be: "inconsistencies yes or no?", but which ones, how and where.