While logical principles seem timeless, placeless, and eternal, their discovery is a story of personal accidents, political tragedies, and broad social change. If A, Then B begins with logic's emergence twenty-three centuries ago and tracks its expansion as a discipline ever since. -/- The book treats logic as more than a tale of individual abstraction; it sees logic as also being a result of politics, economics, technology, and geography, because all these factors helped to generate an audience for the discipline (...) from the start. The book thus relates developments in logical theory to the social history of different historical periods. -/- The book defends a number of controversial philosophical theses: (1) that rationally persuasive arguments must always proceed from premises that are initially more convincing than the conclusions to be proved (a position derived from Aristotle), (2) that intuitive logical judgments, though sometimes mistaken, can also count as certain knowledge, independent of the techniques used to construct formal logical systems, (3) that Wittgenstein was mistaken in thinking that philosophy was riddled with unintelligible language and that the real problems, instead, have been ambiguity and pretentious diction, and (4) that Nelson Goodman's argument to the effect that deductive logic can be "virtuously circular" is founded on a non sequitur. -/- . (shrink)

We are grateful for Roy T. Cook's attention to our work in his recent review of our book If A, Then B: How the World Discovered Logic. But Professor Cook leaves two misimpressions that we should like to correct. First, we have never maintained (as he phrases it) that "one's premises must be more certain than the conclusions that follow from them, ignoring the obvious logical fact that, if B logically follows from A, then B is provably at least as (...) probable as A." Instead, we assert that one must be *initially* more certain of one's premises than the conclusions that follow from them; otherwise, we contend, no argument that relies on those premises to prove such a conclusion can be rationally persuasive. On this view, one might still be equally certain of both the premises and the conclusion after being persuaded by the argument, especially in cases where the premises entail the conclusion. By analogy, Aristotle asserts in the Posterior Analytics that the premises of demonstration must be "better known" than the conclusion—meaning, in part, that the premises must be initially more convincing. But this hardly shows that Aristotle thinks that, if A is invoked to demonstrate B, then A and B can never be regarded as equally probable…. (shrink)

Professor Girle suggests that the ancient Athenian interest in Aristotle’s syllogistic flowed from a preoccupation with debate in the form of a dialogue game. But other cultures, especially in India, also had a preoccupation with debate that could be characterized in the same way. This kind of explanation seems to us to ignore the elephant in the room: the fact that, in ancient Athens, dialogue and debate were not merely a game. They were the life and death of the state. (...) Many Athenians felt that foolish policies had cost the state dearly, especially during the Peloponnesian War, and many of them blamed those policies on shoddy political reasoning in the Assembly. (Plato hammers at this theme relentlessly.) And tellingly, it is only in the wake of such tragedies that Aristotle’s syllogistic finally emerged. We think that any credible explanation of the ancient Greek interest in formal logic needs to include this grim political reality. (shrink)

Why do logical truths exist at all, and how can our belief in them be justified? In an earlier article we contended that at least some aspects of logic must always be assumed, without argument, and that ‘logic is a horizon beyond which none of our earnest and self-reflecting arguments can help us see’. We also contended that logical truths are independent of physical facts, of social rules, and of the anatomical features of our brains. Nevertheless, in a further article (...) in this volume, Jeremiah Joven Joaquin and Jose Emmanuel Agregado have challenged our view. We respond to their criticisms.Export citation. (shrink)