Author: Heidi White
Logic seems like a bookish discipline, but its discovery was actually a response to urban political crisis in the fourth century B.C. More generally, a number of different branches of logic came out of political and economic changes that not only encouraged the work of specific logicians but also generated an audience for the logicians’ discoveries.
A brief word about terminology first:
Many ancient peoples studied “logic” in the broad sense of argumentation. But not all of them studied logic in the specific sense of deductive validity, where a conclusion follows from its premises as a matter of logical necessity. For example, if all cats are cool, and Felix is a cat, then it seems to follow as a matter of necessity that Felix is cool. This is different from saying that, if all cats are cool and Felix is a cat, then Felix should be allowed to eat the family goldfish. The first argument is deductively valid, but the second is not.
The odd thing—the truly striking thing—is that there is no historical record of anyone anywhere in the world ever inventing a study of the deductive validity of argumentation until Aristotle. Philosophers in ancient India and ancient China studied argumentation, but they studied it as a mix of logic and rhetoric—and with no distinction between deduction and induction. All the Greek thinkers before Aristotle also studied argument in this same way—as a mix of logic and rhetoric, and with no distinction between deduction and induction. What set Aristotle apart was that he saw the logical force of a valid argument as depending on an abstract structure that could be represented with variables—As, Bs, and Cs. And it is structures like these that define what professional logicians now mean to analyze. It was Aristotle alone who started studying logic in the sense now intended by professionals. But why is this?
One thing to keep in mind from the start: logical discoveries usually depend on individual insight, but logic as a discipline requires something more—insight with an audience. Logicians need other people who want to listen. And audiences are a consequence of social forces, forces that affect large numbers of people quite apart from individual will. As a result, logic has a social history no less than an abstract one. Logic considers unchanging, abstract truths (or at least they seem that way), but the extent to which large numbers of people will ever really explore these truths still depends, in part, on their social setting. And their social setting turns on various factors—political, economic, technological, even geographical. The history of logic is, therefore, a mix of the abstract and the mundane.
The development of Greek logic turned on at least two crucial factors—one geographical, the other political.
First, the geography of classical Greece favored small states, dominated by large urban crowds, like the Athenian demos, meaning the common people, as opposed to aristocrats. The ease of navigating the Mediterranean Sea caused the commercial classes in the Greek city-states to grow larger—especially in the wake of the second Persian War, from 480 to 479 B.C.E. After the war, Greek navies gained control of the Aegean Sea. And the small size of these states—a consequence of the many mountains and islands of Greece—meant that these same commercial crowds ended up dominating the politics of the classical age. The old aristocracies that had governed populations of peasants gave way increasingly to urban middle- classes. As a result, political questions were settled not in the palaces of kings or in small councils of nobles but in urban mass meetings like the Athenian Assembly. And the mechanics of these mass meetings put special emphasis on public argumentation. If you wanted power, you had to win votes. And to win votes, you had to argue publicly.
The second crucial factor, in addition to the geography, is that these same crowds, when called to make political decisions, often behaved irrationally—a theme that was perhaps best articulated by Plato, who constantly blamed the teachers of public speaking (the Sophists) for the troubles of Greece. And it was just this environment that ultimately caused Aristotle’s listeners to pay special heed to his specific concern with validity.
Plato had stressed the difference between the rational and the merely persuasive, and an entire generation of Plato’s readers had come of age under the influence of this distinction. They came to believe (as Plato believed) that rational arguments were different from merely persuasive ones, and they also believed, like Plato, that inattention to the distinction had undermined Athens during its long war against Sparta—the Peloponnesian War—and had even led to the execution of the philosopher Socrates. Of course, many ancient peoples distinguished between the rational and the irrational, but in Athens, the distinction was a matter of special sensitivity, even bitter sensitivity, because of the recent political history.
Explanations of the kind I suggest here are necessarily conjectural. We can’t see into the souls of people long gone and know with certainty why they found some subjects more interesting than others. Aristotle says (in the Prior Analytics) that he investigates syllogisms to establish the proper conditions of scientific knowledge. But the importance of “science” or “knowledge” (or episteme) was already an established Platonic theme, and for Plato, it was definitely a political theme. In the ideal state of Plato’s Republic, the true philosopher-rulers have knowledge, or episteme, whereas most people—the people who dominate the Assembly— are said to deal only in “opinion” or “doxa.” Aristotle had been a member of Plato’s Academy for roughly twenty years, where such attitudes would have been deeply entrenched, and many of his contemporaries would have been familiar with these recurring Platonic ideas.
The underlying mechanism I mean to describe is a chain of cause and effect: Greek geography gave rise in the fifth century B.C.E. to an unusual political system—the system of simple democracy—and a crisis in this system then generated an intellectual and ideological reaction that culminated in the discovery of validity as a distinct field of inquiry.
But the geography I invoke deserves more attention than I’ve given it so far.
The mountains of Greece are particularly rugged, the valleys between them especially small. But these valleys, filled with rich alluvial soil from the hills, generally end with the sea, and the sea in question happens to be the most extensive yet protected sea anywhere in the world. The Mediterranean is quite unique. It is effectively the world’s largest lake. Cut off from the great tides and immense waves of the world’s oceans, the Mediterranean was particularly favorable to ancient seafaring, a point stressed by Adam Smith, who argued that most ancient civilizations were located along waterways because waterways facilitated trade.[1] And in economic and political terms, the effect of these geographical accidents was then to accelerate tendencies that would later recur repeatedly in the modern world.
Debate was one of these tendencies. Increasingly filled with merchants and artisans of similar social station, the governments of these small states debated a great range of questions. They debated war and peace, public works, the regulation of trade, the correct way (or what they thought was the correct way) of propitiating the gods, and countless other matters. Nor were these debates filtered through a medium of elected representatives.
Eventually, the most argumentative of any classical Greek environment was the city of Athens, and the reason was the city’s Assembly.
The Assembly made treaties, sent soldiers into combat, and often debated just how many warships to send to a particular theater of operations. In at least one instance, the Assembly condemned to death the entire adult male population of a subjugated island (Melos).[2] In another instance, it executed six of its own generals for misconduct. (These were six of the eight generals from the battle of Arginusae in 406 B.C.E.)[3] And it made all these decisions by simple majority vote.
The Assembly’s policy was probably steadiest and shrewdest under Pericles, but even Pericles, near the end of his career, was voted out of office and fined. Yet this didn’t last, either. The historian Thucydides remarks, “Not long afterwards, as is the way with crowds, they re-elected him to the generalship and put all their affairs into his hands.”[4]
This Athenian tendency toward vacillation made a deep impression on James Madison, one of the principal architects of the U.S. Constitution. In The Federalist Papers, Madison characterized the Athenians as forever “decreeing to the same citizens the hemlock on one day and statues on the next.” But my purpose in making these points is neither to condemn the Athenians nor to praise them. Instead, my purpose is to stress just how unusual the Athenian case was. The Athenian case was the extreme case. Other societies have approached the Athenian example to greater or lesser degrees, but none have ever equaled it for any prolonged period. In Athens, popular opinion was everything, and popular opinion was everywhere dominated by public speaking. Thus, the ability to construct an argument was far more important in their daily life than in the life of any other people—before or since.
Is it really so strange that the history of logic should start here?
My talk comes in part from a book I published with my colleague Michael Shenefelt, If A, Then B: How the World Discovered Logic, from Columbia University Press.
Featured Image: Reconstruction of Athens – Friedrich von Thiersch, drawing, circa 1900.
Footnotes
[1] Smith makes this point in the third chapter of Book I of The Wealth of Nations, first published in 1776.
[2] In 416 B.C.E., the Athenians besieged the neutral island of Melos to demand that it join the Athenian empire. The Melians refused but were eventually forced to surrender. The Athenians then executed all males of military age, sold the women and children as slaves, and finally repopulated the island with five hundred of their own colonists. Thucydides relates these events at 5.84-116 in his History of the Peloponnesian War.
[3] The generals had won a desperate sea battle against the Spartans, but they had also left more than a thousand Athenian soldiers and sailors, who were clinging to wreckage in the sea, to drown. The generals said they had abandoned the men out of military necessity, but the relatives of the dead then accused the generals of murder and had them tried in the Athenian Assembly—rather than in a law court. The six generals who appeared for the trial were executed, including Pericles, son of the famous orator.
[4] Thucydides, 2.65. According to Thucydides, the Assembly condemned Pericles out of despair over the Plague. But the Athenians then reinstated him because, finally, “they regarded Pericles as the best man they had.”