Oswaldo Chateaubriand Filho is Professor Emeritus at the Pontifical Catholic University of Rio de Janeiro (PUC-RJ), Brazil. PhD in Philosophy from the University of California, Berkeley, USA, he is member of the Centre for Logic, Epistemology and the History of Science (CLE) at the University of Campinas (UNICAMP) and titular member of the Institut International de Philosophie, Paris. He taught in the Philosophy Department at the University of Washington, in Seattle, in the Philosophy Department at Cornell University, and in the Graduate Program of Psychology of the Getúlio Vargas Foundation (FGV, Brazil), having been visiting professor in the Mathematics Department at the University of São Paulo (USP, Brazil) and in the Philosophy Department at Harvard University, USA. He is a founder member of the Brazilian Logic Society (SBL), having been its president for two terms. His working areas are philosophy of logic, philosophy of mathematics, and philosophy of language.