QuestionsWhat is a just society?Light taxes yield more, injustice ruins the state
What is a just society?Liberties

Light taxes yield more, injustice ruins the state

Ibn Khaldun 1332 · 1406Civilisations rise and fall with the strength of their solidarity.
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What it claims

A just government must tax lightly and respect its subjects' property and labour; that is also what makes the state rich, whereas injustice ruins it.

Why

Light taxes encourage activity, which brings the state more; excessive taxes kill the will to work and ruin everything.

In short

"Light taxes yield more, injustice ruins the state" is an argument by Ibn Khaldun (Muqaddima, I, 3, 36-41) on the question "What is a just society?" (answer: liberties). Its claim: A just government must tax lightly and respect its subjects' property and labour; that is also what makes the state rich, whereas injustice ruins it. According to AskPhilosophy's logic check (Z3 solver), the conclusion does follow from its 6 premises. AskPhilosophy presents 3 objections, 1 of them with a documented reply, and the original text behind each premise, checked word for word.

Muqaddima, I, 3, 36-41
Valid

At the beginning of a dynasty, taxes are light and bring in a lot; at the end, they are heavy and bring in little. Ibn Khaldun, who served several princes himself, explains this paradox: what makes the state rich is the work of its subjects, and they work only if they hope to keep the fruit of their efforts. He then widens the idea to every injustice: confiscating, imposing forced labour, forcing merchants to buy dear and sell cheap. Six centuries later, the idea that beyond a certain rate taxes bring in less was called the "Laffer curve".

P1When taxes are light, people have the desire and energy to undertake things: they farm, build and trade more.
P2The more activity there is, the more people and goods there are to tax: small taxes on abundant activity make a large revenue.
P3When taxes exceed the bounds of equity, people compare their burdens with their gains, lose hope and stop undertaking anything. Total revenue falls, and raising taxes further is of no use.
P4More broadly, any attack on people's property and labour (confiscating, imposing forced labour, demanding what is not owed, levying a tax the law does not provide for) is an injustice, and takes away their wish to earn a living.
P5The state is like the form of civilisation, and people's activity its matter: when the matter decays, the form decays with it.
P6That is why divine law forbids injustice: what ruins civilisation cannot be a just way of governing.
Therefore a just government must tax lightly and respect its subjects' property and labour; that is also what makes the state rich, whereas injustice ruins it.

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.
The argument is valid with no hidden premise. A just government does not ruin people's activity (P6); yet heavy taxes (P3) and attacks on property (P4) ruin it: so it must tax lightly and respect property. Light taxes make activity grow (P1), hence revenue (P2); injustice undoes activity, hence the state (P4, P5). The debate is about the factual premises, above all P3: from what rate does taxation really discourage work?
Analogy. A shepherd who shears his sheep every spring has wool every year. If he shears them to the skin, then slaughters them for their meat, he earns more that year, and nothing afterwards.

Objections

3

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

M
Modern economists attacks premise 3

The idea is right in principle, but everything depends on the rate. Most studies put the revenue-maximising rate well above usual tax levels, and many recent tax cuts, in the United States for instance, did not bring in more than they cost. Cutting taxes does not always raise state revenue.

no reply
summary: their text is not yet in our corpus
No reply possible: objection raised after the author's death (1406).
The debate goes on (our summary) Ibn Khaldun does not say that every tax cut enriches the state. He describes taxes piling up "beyond the limits of equity" to pay for the court's luxury, in economies of farmers and merchants where labour quickly flees to another region. Economists still debate where that threshold lies, depending on countries and periods. (Our summary.)
M
Modern public economics attacks premise 2

Taxation is not only a discouraging burden: it pays for roads, schools and security, which make people more productive. A state that taxes little can also grow poor by failing to spend on what keeps the economy alive.

Ibn Khaldoun replies
summary: their text is not yet in our corpus
Ibn Khaldoun
The state and the ruler are the world's greatest market, providing the substance of civilisation. If the ruler keeps the money to himself or does not spend it properly, his entourage spends less, trade slumps and tax revenue falls: money only passes from the subjects to the ruler and from the ruler to the subjects.
The debate goes on (our summary) So Ibn Khaldun saw that state spending keeps the economy alive. But he thinks of it through the court, the soldiers and the officials, not through public services for all: these hardly existed in his time. (Our summary.)
Rousseau 1755 · attacks premise 4

Defending everyone's property is not necessarily just: the laws that protect property were invented by the rich, who persuaded the poor to defend their own chains. A just society first corrects inequalities.

no reply
No reply possible: objection raised in 1755, after the author's death (1406).
The debate goes on (our summary) Both thinkers denounce the plundering of the weak by the powerful, but they do not target the same culprits. The property Ibn Khaldun wants to protect is that of peasants, craftsmen and merchants, against the ruler and his courtiers: injustice, he writes, is committed only by those who hold power. Rousseau suspects property itself. (Our summary.)