THE WORLD is logical, according to some. Others call it absurd. We have never been sure who is right, but what we do know is that nobody grasps the absurd unless that person also senses the logical. Yet, in that case, where does our sense of logic come from? What is it really a sense of? And what drove people to start studying logic in the first place?
There are excellent histories of logic already in circulation (including the magisterial Development of Logic by William and Martha Kneale, Oxford University Press, 1962). And thanks to online sources, there are also many able accounts of the latest work in the field, including nonclassical symbolic logic. Nevertheless, we believe our book to be fundamentally different from previously published works. Earlier histories of logic have focused on the specific stories of individual logicians, relating their discoveries, their intellectual influences, and their personal predicaments. But logic is the work of more than logicians alone; logicians, like other writers, need readers, and the forming of a readership is just as vital to the survival of a logician’s insights as the logician’s individual circumstances. In logic, as in other departments of intellectual history, a readership is a consequence of social forces—forces that affect large numbers of people, quite apart from individual will. As a result, if one then leaves out of consideration the forces shaping such a readership (or the forces shaping a logician’s audience), one is in danger of missing much of the explanation of why logical discoveries show up when and where they do.
Aristotle, for example, inherited a rich philosophical legacy in classical Greece, but equally important, in our view, was the reaction of significant numbers of his contemporaries—his audience—to the follies of the Athenian Assembly, an institution that owed its existence, indirectly but no less crucially, to Greece’s peculiar geography. Aristotle’s work required not only an intelligent thinker to invent it but also an appreciative audience to preserve it, and what made Aristotle’s work interesting to this audience in the first place was its connection to the argumentation of the Assembly and to the political disasters of his age. The Athenians had already suffered through immense political tragedy, especially during the Peloponnesian War, and in acting out this tragedy, they had prepared the ground for Aristotle’s insights. Logic captured their interest from the start because many of them believed their politics had already been undermined by sophistry.
Suppose, then, one were to ask, “Why did the originator of formal deductive logic emerge in classical Greece rather than in, say, classical India or classical China, which also offered rich philosophical legacies?” We believe much of the answer lies not in Aristotle’s personal training and experience but in a broader set of economic and political conditions—conditions encouraged by the physical environment—that had made classical Greek society especially sensitive to public argumentation and highly vulnerable to its political effects. To be sure, these circumstances would have been almost as much a part of Aristotle’s experience as anyone else’s, but the key point is that the circumstances were general, not specific to an individual, and in our view, it is precisely such general circumstances that have been underrated.
More broadly, to treat logic’s history as if it were only a matter of individuals, without considering the larger forces shaping the audience and the logician alike, would be like treating political history as if it were only a matter of individuals—as a tale of specific rulers or rebels but with no account of why large numbers of contemporaries reacted to their actions in any particular way. It would be like treating political history as only a story of the insights, villainies, and sacrifices of particular persons, with no social analysis.
In making these claims for the importance of social forces in the development of logic, we in no way deny the significance of the individual in history; rather, we contend that historical changes can have many different causes. The social process can be an important force—just as important as the individual. And in stressing this point, we see ourselves not as contradicting earlier work in the history of logic but as offering a further level of explanation.
We are much indebted in our efforts to a number of colleagues and friends for their suggestions, though we are sure that, in many instances, we should have been more attentive to their criticisms. The errors that remain are ours. We would especially like to thank Douglas R. Anderson, Lloyd Carr, Elizabeth Potter, and Phil Washburn. We would also like to thank Parvaneh Badie for her lucid and instructive diagrams, which we have used in conveying various logical principles to those with no previous formal training in the field.
In addition, we are grateful to the organizers of the Eighth Panhellenic Logic Symposium in Ioannina, Greece, where, in 2011, we had the opportunity to present part of our argument to the effect that economic and political conditions played a crucial role in Aristotle’s discoveries. We also want to express our thanks to the organizers of the 2012 Logic Colloquium in Manchester, England (sponsored by the British Logic Colloquium, the London Mathematical Society, the Association for Symbolic Logic, and the Manchester Institute for Mathematical Sciences) for the chance to offer our thesis that the nineteenth-century Industrial Revolution spurred the invention of symbolic logic. At each of these conferences, we received valuable criticism from members of the audience, and we have tried to work their points into our text.
We owe a great debt of gratitude to our agent, Diana Finch. Diana gave us crucial encouragement and a good deal of deft editing. We would like to thank as well our editor Wendy Lochner of Columbia University Press for her care and support of our project. Our thanks go also to Christine Dunbar for her expert guidance in preparing the final version of the manuscript for publication.
In earlier works on the history of logic, there has long been a tradition of treating logical discoveries as if they were the stunning and beautiful work of individual, brilliant minds. Notwithstanding our remarks on the role of social forces, we believe this tradition to be correct. The great, individual logicians of the past were brilliant minds, their discoveries are beautiful, and logic as a whole is in many ways mysterious and sublime. In the pages that follow, we hope to convey some of the majesty of this ancient and noble discipline.