This chapter focuses on alternative logics. It discusses a hierarchy of logical reform. It presents case studies that illustrate particular aspects of the logical revisionism discussed in the chapter. The first case study is of intuitionistic logic. The second case study turns to quantum logic, a system proposed on empirical grounds as a resolution of the antinomies of quantum mechanics. The third case study is concerned with systems of relevance logic, which have been the subject of an especially detailed reform (...) program. Finally, the fourth case study is paraconsistent logic, perhaps the most controversial of serious proposals. (shrink)

The purpose of this article is to show how W.B. Gallie’s proposal on the essential contestability of political concepts ended up calling into question the very notion of essential contestability proposed by this author. In spite of this, we consider that such a notion can still be a contribution to the history of concepts if it is complemented by some aspects of Hegel’s philosophy, located in his Science of Logic, which can provide a foundation for such contestability from a self-referred (...) negativity open to semantic displacements, which allows us to receive Gallie’s proposal without having to accept all his theoretical commitments, radicalizing his proposal and providing some useful indications for the history of political concepts. (shrink)