Course 1

Paraconsistent Reasoning in Historical and Epistemological Perspectives

Evndro Luís Gomes
CLE/State University of Maringá – UEM, Brazil
(with the assistance of Itala M. Loffredo D’Ottaviano)


The study of the logical meaning of consistency and inconsistency is found throughout the various periods of the history of philosophy, science and logic. Analyzing the historical precedents of paraconsistent logic before the 20th century, we can try to respond several unanswered questions. In this course we will survey the most distinguished logical contributions and theoretical discoveries on the Western thought tradition in order to understand how a truly paraconsistent perspective has been constituted, as well as how logical principles, rules and systems could have expressed the various concepts of paraconsistency. In the history of logic, we will track answers for some fundamental questions, as if logical principles and rules, according to which not everything may be deduced from a contradiction, or something may be rejected, were conceived, evoked or introduced within certain theoretical contexts and traditions. We will employ advanced historiographical categories to deal with logical contributions to the history of paraconsistent logic, providing a critical assessment of paraconsistent-like positions in ancient Greek logic, medieval scholastic logic, and modern logic as well as in paraconsistent logic systems era. In the establishment of the paraconsistent logic, we will stress the crucial contributions of Stanislaw Jaskowski (1948) and Newton da Costa (1963), with special emphasis to the legacy of these fundamental contributions to the further development of paraconsistency as a fruitful field of research. We also study the key contributions of diverse schools of paraconsistent logic as the Polish, the Brazilian, the Australasian and the Israeli, as well as we discuss the main contributions of other research groups working on paraconsistency, what makes paraconsistency an academic worldwide enterprise in the present time.