QuestionsWhat makes something right?The fable of the Troglodytes
What makes something right?Virtue

The fable of the Troglodytes

Montesquieu 1689 · 1755To prevent abuse, power must check power.
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What it claims

Thinking only of oneself is not our true interest: each person's interest lies in the common interest, and "in acting justly by others, we bestow blessings on ourselves".

Why

A people where everyone thinks only of himself, with no sharing, judges or kept promises, destroys itself.

In short

"The fable of the Troglodytes" is an argument by Montesquieu (Persian Letters, 11 to 14 (Usbek)) on the question "What makes something right?" (answer: virtue). Its claim: Thinking only of oneself is not our true interest: each person's interest lies in the common interest, and "in acting justly by others, we bestow blessings on ourselves". According to AskPhilosophy's logic check (Z3 solver), the argument is valid only if one grants a premise the author leaves unstated (P3). AskPhilosophy presents 2 objections, 2 of them with a documented reply, and the original text behind each premise, checked word for word.

Persian Letters, 11 to 14 (Usbek)
Valid with an implicit premise

His friend Mirza asks Usbek whether happiness comes from pleasures or from virtue. Usbek answers not with reasoning but with a fable, because moral truths must be "felt". A small people of Arabia, the Troglodytes, decides that each will think only of himself. No more sharing, no more judges, no more promises kept: they perish. Two just families survive and found a happy people. Note: a character in the novel is telling the story, and the fable has a less rosy sequel.

P1When each looks only to his own interests, without regard for others', no one shares, settles quarrels or keeps his word any more.
P2A people where no one shares, judges or keeps his word destroys itself: the Troglodytes "perished in their sins".
P3 · implicit premiseWhat leads each person to ruin is not his true interest.
Therefore thinking only of oneself is not our true interest: each person's interest lies in the common interest, and "in acting justly by others, we bestow blessings on ourselves".

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 P3, the computer finds a case where selfishness does lead to ruin, and yet remains each person's "interest": nothing yet says that ruining oneself is against one's interest.
With P3, the conclusion follows. But a fable is not a proof: the author decides that the selfish perish. Usbek knows it, since he says he wants to make a truth "felt" rather than demonstrate it. So the real question is: are P1 and P2 true in the real world? Couldn't a clever egoist profit from others' justice without being just himself?
Analogy. In a block of flats, if everyone throws their rubbish on the stairs to save time, after a month everyone lives in filth, including the one who thought he was being clever.

Objections

2

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

G
Glaucon, in Plato's Republic 375 BC · attacks premise 3

Ruin strikes the group, not necessarily each individual. Give a man the ring of Gyges, which makes him invisible: he will take, kill and seduce without punishment. No one is just of his own will, only from constraint. The injustice of one person among just people may well be in his interest.

Montesquieu replies
Montesquieu Usbek's reply, in another letter (Persian Letters, 83)
When a man examines himself, what satisfaction to find that his heart is just! This pleasure, severe as it is, must delight him: he sees himself as far above those who lack it as he sees himself above tigers and bears.
The debate goes on (our summary) This is Plato's own answer: justice is the good of the soul. But it will only convince someone who already feels that satisfaction. Glaucon could reply that the invisible unjust man sleeps very well. The fable shows that a people of egoists destroys itself; it does not show that a lone egoist among just people loses out.
Bernard Mandeville 1714 · attacks premise 2

A society of egoists does not necessarily perish: it can prosper. In The Fable of the Bees, private vices (vanity, love of luxury, greed) drive trade and enrich the hive. Make the bees virtuous, and the hive grows poor.

Montesquieu replies
summary: their text is not yet in our corpus
Montesquieu Montesquieu, later (The Spirit of the Laws, 1748)
In a monarchy, honour sets all the parts of the body politic in motion; by its very action it connects them; and thus each individual advances the public good while he only thinks of promoting his own particular interest. True it is that, philosophically speaking, it is a false honour which moves all the parts of the government, but even this false honour is as useful to the public as true honour could possibly prove to private people.
The debate goes on (our summary) The fable itself hinted at it. When the Troglodytes grow numerous they want a king, and the old sage weeps: "uprightness becomes a burden to you". Under a king, laws "less exacting than your present customs" will do, and one can grow rich without virtue (letter 14). The full lesson is therefore subtler: pure selfishness without rules destroys a people; but well-made laws and institutions can draw the common good out of private interests. What Montesquieu keeps saying is that virtue is finer, and more fragile.