QuestionsDoes history have a direction?Constitutions turn in a cycle: Polybius's anacyclosis
Does history have a direction?Cycles

Constitutions turn in a cycle: Polybius's anacyclosis

Anacyclosis, the cycle of constitutions

Polybe 200 BC · 118 BCGreek historian: constitutions change into one another in a natural cycle.
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What it claims

Political history follows a natural cycle: regimes are born, grow, decline and return, and no constitution escapes decay, not even Rome's.

Why

Each pure regime degenerates into its evil twin, and generations that forget the evil make regimes turn in a cycle.

The same idea through history
Niccolò Machiavelli1531Machiavelli takes up Polybius's cycle in book I of the Discourses, correcting it: a republic rarely goes round the whole cycle more than once, because it is often conquered first. See his argument on conflict and liberty.
In short

"Constitutions turn in a cycle: Polybius's anacyclosis" is an argument by Polybe (Histories, book VI, 3-9 and 57 (c. 150 BC)) on the question "Does history have a direction?" (answer: cycles). Its claim: Political history follows a natural cycle: regimes are born, grow, decline and return, and no constitution escapes decay, not even Rome's. According to AskPhilosophy's logic check (Z3 solver), the argument is valid only if one grants a premise the author leaves unstated (P4). AskPhilosophy presents 3 objections, 3 of them with a documented reply, and the original text behind each premise, checked word for word.

Histories, book VI, 3-9 and 57 (c. 150 BC)
Valid with an implicit premise

Polybius, a Greek taken to Rome as a hostage after Macedonia's defeat, tries to understand how Rome brought nearly the whole known world under its power in less than fifty-three years. In book VI he describes constitutions as living beings. He distinguishes three good forms (kingship, aristocracy, democracy) and three bad ones that corrupt them (tyranny, oligarchy, mob-rule). They follow one another in a natural order, and then the cycle begins again. Rome escapes it for a long time thanks to a mixed constitution, but not forever. Note: book VI survives only in excerpts, and the translation quoted (1889) is old.

P1There are six forms of government: three pure (kingship, aristocracy, democracy) and three that corrupt them (tyranny, oligarchy, mob-rule). Each pure form naturally degenerates into its bad form, which is overthrown in favour of the next.
P2The mechanism is that of generations: when a new generation succeeds the one that suffered, long habit weakens in it the value of equality and freedom, and some seek power.
P3This is the regular cycle of constitutional revolutions: the natural order in which constitutions change, are transformed, and return again to their original stage.
P4 · implicit premiseIf each regime is pushed by its own natural causes toward the next, and the last leads back to the first, then political history repeats itself in cycles.
Therefore political history follows a natural cycle: regimes are born, grow, decline and return, and no constitution escapes decay, not even Rome's.

click a premise to reject it

If you accept every premise, logic forces you to accept the conclusion. So the debate is about the premises.
Checked by a logic solver: the premises cannot all be true while the conclusion is false.
Without the implicit premise: Without P4, the computer finds a world where generations forget and regimes corrupt, but where the passage from one regime to another varies with circumstances: a tendency, without a regular cycle.
Valid with P4. P4 moves from a mechanism (a generation forgets) to a law of repetition (regimes always return in the same order). Without P4, one can grant that forgetting plays a role without the order of regimes being fixed. Polybius himself grants that one can be wrong about the dates, but rarely about the stage reached (VI, 9).
Analogy. The ages of a life: birth, strength, old age, death, then other births elsewhere. Polybius compares constitutions to living bodies. As a doctor knows where a patient stands without predicting the date of death, the historian knows where a city stands without predicting its exact day.

Objections

3

Each objection is a conversation: click to see who replies and where the debate stands.

Objection anticipated by Aristotle 330 BC · attacks premise 3

Constitutions more often change into the opposite form than into the neighbouring one. Tyranny does not always change into the next form: it passes also from tyranny to tyranny or to oligarchy. There is no single order, hence no cycle that returns to the starting point.

Polybe replies
We have not yet found a direct reply by Polybe in the texts.
Polybe Passage by Polybius, later than Aristotle (who is not named)
Polybius does not claim to predict dates or every detail. Whoever has grasped the cycle may be wrong about when a given change will come, but will rarely be entirely mistaken about the stage of growth or decay a constitution has reached. The cycle is presented as a dominant order, not a law without deviation.
The debate goes on (our summary) Aristotle writes before Polybius and targets Plato's cycle (Republic VIII, criticised in Politics V, 12); Polybius recognises that Plato and others treated it "with greater accuracy" but too intricately for most people (VI, 5), and gives a simplified version, based on the psychology of generations. He admits a margin of error on dates (VI, 9) and an external, unpredictable cause (VI, 57). We have found no reply by Polybius that directly discusses changes "toward the opposite". (Our summary.)
Where the debate stands (our summary)Core disagreement: is there a single order of succession of regimes, or only tendencies to corruption? Polybius's scheme remains a tool for comparison, debated as a law. Open point.
Machiavelli 1531 · attacks the conclusion

This is the circle in which all States revolve, but it is rare that they fall back into the same governments: hardly any republic has enough life to go through these changes several times. It often becomes subject to a better-ordered neighbour before completing them.

Polybe replies
see the argument
Polybe Passage by Polybius, written before the objection
Polybius distinguishes two natural sources of decay: one external, which cannot be defined with certainty, the other internal, which follows a definite order. It is the internal order that he describes.
The debate goes on (our summary) The two authors agree: the cycle is a scheme of internal corruption. Machiavelli concludes that conquest by a neighbour is, in practice, the most frequent end. For him, the conflicts between the great and the people, far from an evil, helped Rome remain free; Polybius sees above all the strength of a balance of powers. (Our summary.)
Where the debate stands (our summary)Limited disagreement: is the cycle really completed, or is it mainly a reading grid for understanding decline? Both authors retain the mixed constitution as a partial remedy. Open question.
Hegel 1837 · attacks the conclusion

Changes in nature show only a cycle that repeats forever, and nothing new happens under the sun. Only in the realm of spirit does something new appear: human history is therefore not a circle, but a capacity for change toward the better.

a defender replies
see the argument
No reply possible: objection raised in 1837, after the author's death (-118).
Giambattista Vico defender of the argument · 1744
Vico defends a cyclical history that is not that of nature. The course of nations is neither fate, because men made it by choice, nor chance, because by always acting so they arrive at the same things. The return comes from what men do, not from a necessity of nature. (Text earlier than Hegel, who is not named.)
see the argument
Karl Popper 1957
Popper puts this doctrine, from Plato to Vico and Spengler, among those that apply to a society the life cycle of an organism. The cases of repetition involve very different circumstances, which may change what follows: a resemblance does not make a law, even if men act by choice.
see the argument
The debate goes on (our summary) Hegel (lectures of 1822-1831, published after his death by his students) does not cite Polybius in this passage, but opposes the cycle of nature to the novelty of spirit. Polybius himself describes regimes that are born, grow and decline like organisms, which is exactly what Hegel calls the natural. It remains to decide whether human affairs are closer to organisms or to spirit. (Our summary.)
Where the debate stands (our summary)Core disagreement: is history a natural cycle that repeats, or a process in which spirit brings forth novelty? Vico accepts the return while saying men make it; Popper denies that resemblances make a law. Open question.