In a message dated 3/14/2002 5:47:08 PM Central Standard Time, robin@BILKENT.EDU.TR writes:Well, I take your word for it. Chrysippus is so hard to follow that other He would. Within a couple of generations of Chrysippus, the rhetoricians got ahold of Stoicism and logic went into decline (nosedive). Cicero, a rhetorician and a sort of Stoic, wrote probably the worst logic book before Kant or Hegel (he got Aristotle and the Stoics jumbled together and there they stayed for a millennium). It's hard to explain an algorithm 500 years before Brahmagupta and 700 before Al-Kwarizmi, but what little we know about Chrysippus strongly suggests that he had decidability of propositional logic down. But he backed the wrong implication apparently (formal or modal or temporal rather than material). |