(I wonder if it's just a coincidence that it was originally posted on Hegel's birthday!)
First published Fri Aug 27, 2004
The ‘Dialectical school’ denotes a group of early Hellenistic philosophers that were loosely connected by philosophizing in the — Socratic — tradition of Eubulides of Miletus and by their interest in logical paradoxes, propositional logic and dialectical expertise. Its two best-known members, Diodorus Cronus and Philo the Logician, made groundbreaking contributions to the development of theories of conditionals and modal logic. Philo introduced a version of material implication; Diodorus devised a forerunner of strict implication. Each developed a system of modal notions that satisfies the basic logical requirements laid down by modern standard modal theories. In antiquity, Diodorus Cronus was famous for his so-called Master Argument, which aims to prove that only the actual is possible.
Historical and Biographical Information
The name ‘Dialectical school’ is used for a group of philosophers active from the later 4th to the mid 3rd centuries BC who are referred to as members of the Dialectic sect (hairesis) or as dialecticians (dialektikoi) in some later ancient sources (Diogenes Laertius 1.19). They were traditionally counted among the philosophers of the Megaric school (founded by Euclides of Megara), but may have formed an independent branch of this sect. Together with the Megarics, Cyrenaics and Cynics they count among the minor Socratic schools. Their main philosophical interest was in dialectical skill and accomplishment, including the development and resolution of logical paradoxes. They also made several important positive contributions to the development of propositional logic. It is uncertain whether the members of the Dialectical school were connected by an institution comparable to other ancient philosophical schools, or whether their union under one name in later reports was based more loosely on their common philosophical interest in dialectic.