Formal logic

The logico-philosophical tradition has widely taken for granted certain principles, such as the principles of excluded middle and non-contradiction. However, during the twentieth century, logical investigations underwent a revival which contributed to a requestioning of their status as basic principles of logic. On the sidelines of classical logic, many non-classical logics, which do not obey some of these principles, have been developed.

Through an analysis of the notion of valid reasoning specific to some non-classical logics that are para-consistent (allowing to reason with inconsistent information) or para-complete (allowing to reason with incomplete information), this course aims at investigating the fundamental principles of classical logic.