Scholars and members of the  Brazilian academic circles, colleagues and friends around the world  are deeply saddened by Professor Newton Carneiro Affonso da Costa passing last Wednesday, April 17th, aged 94 years, due to a  lamentable domestic accident.

Newton da Costa, as he was known, one of the most internationally renowned logicians, systematized for the first time the study of paraconsistent logics (that is, logics that admit contradictory yet non-trivial theories) in his Chair Thesis “Teorias Formais Inconsistentes” (Inconsistent Formal Systems), defended in 1963 at the Federal University of Paraná. From his innovative proposals, studies in paraconsistency experienced strong growth, not only in Brazil but also abroad, giving rise to what is now known as the Brazilian School of
Paraconsistency. Given the importance of these logics in the international academic scenario, in 1991 the entry “03B53: Paraconsistent Logic” was created in the “Logic and Foundations” section of the Mathematics Subject Classifications jointly elaborated by Mathematical Reviews and Zentralblatt für Mathematik.

In addition to his  important contributions in the area of non-classical logics, Newton da Costa made unique contributions in the areas of Foundations of Mathematics, Foundations of Physics, and Philosophy of Logic.

Newton da Costa was Full Professor and Associate Director of the Institute of Mathematics, Statistics, and Computer Sciences at the University of Campinas (Unicamp) shortly after its creation, from 1968; Full Professor at the Institute of Mathematics and Statistics at the University of São Paulo (USP), and later at the Department of Philosophy of the Faculty of Philosophy, Letters, and Human Sciences at USP.

He participated in the creation of the Centre for Logic, Epistemology and  the History of Science (CLE) at Unicamp in 1977. Among his activities at CLE, he participated in the founding of the Brazilian Society of Logic (SBL), being its first president in 1979, as well as in the creation, in 1982, of The Journal of Non-Classical Logic, the first journal of international circulation in the area of non-classical logics. He was one of the responsibles for the realization of the “Brazilian Logic Conferences” and of the “Latin American Symposia of Mathematical Logic”.

Newton da Costa was a member of the Académie Internationale de Philosophie des Sciences (AIPS) and of the Institut International de Philosophie (IIP).  Among several prizes and honors, he was awarded the “Moinho Santista Prize in Exact Sciences” in 1994 and the “Jabuti Prize in Exact Sciences” in 1995, both prestigious Brazilian awards, as well as the “Nicolau Copernicus Medal” in Poland in 1995. In 2023, the “São Paulo School of Advanced Science on Contemporary Logic, Rationality, and Information (SPLogic)” was held at CLE-Unicamp in honor of his 90th+ birthday, gathering more than 150 international students and scientists from around the world.

In 2009, the annual AIPS Meeting was held at CLE, Unicamp, in honor of his 80^th birthday and he was named Professor Emeritus of Unicamp. Honorary Professor of the Federal University of Santa Catarina (UFSC) in 2010, he continued to serve as a guest and volunteer professor in the Department of Philosophy at UFSC until recently.

With hundreds of published works, which receive thousands of citations, Newton da Costa was one of the most internationally recognized Brazilian academics. His scientific and philosophical legacy had a profound impact both within and outside Brazil and will certainly continue to be alive for generations to come.

Professor da Costa is survived by students, colleagues, friends, and family members who will deeply mourn his loss.