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Mental Models

Political Logic

Political logic refers to the application of formal reasoning and axiomatic approaches to political systems, as championed by mathematicians like Hilbert and Gödel. However, it has limits, as illustrated by Hilbert's inability to grasp the Nazi consolidation of power.

THE IDEA

POLITICAL LOGIC

Political logic is not a formal system in the sense that Hilbert and the mathematical logicians meant, but mathematicians with a formalist outlook couldn't help but approach politics with the same kind of methodological sympathies. They were encouraged in this by Hilbert himself, who in his 1918 lecture “Axiomatic Thought” advocated that the other sciences adopt the axiomatic approach that had been so successful in mathematics.

For example, Gödel, whose theorem ruled out the possibility of definitively banishing contradiction from arithmetic, was also worried about the Constitution, which he was studying in preparation for his 1948 U.S. citizenship test. In his view, the document contained a contradiction that could allow a Fascist dictatorship to take over the country in a perfectly constitutional manner. Gödel’s friends Albert Einstein and Oskar Morgenstern begged him to avoid this matter in his exam, but, as Morgenstern recalls it, the conversation ended up going like this:

The examiner: Now, Mr. Gödel, where do you come from?

Gödel: Where I come from? Austria.

The examiner: What kind of government did you have in Austria?

Gödel: It was a republic, but the constitution was such that it finally was changed into a dictatorship.

The examiner: Oh! This is very bad. This could not happen in this country.

Gödel: Oh, yes, I can prove it.

Fortunately, the examiner hurriedly changed the subject and Gödel’s citizenship was duly granted. As to the nature of the contradiction Gödel found in the Constitution, it seems to have been lost to mathematical history. Perhaps for the best!

—

Hilbert’s commitment to logical principle and deduction often led him, like Condorcet, to adopt a surprisingly modern outlook in non-mathematical matters.* At some political cost to himself, he refused to sign the 1914 Declaration to the Cultural World, which defended the kaiser’s war in Europe with a long list of denials, each one starting “It is not true”: “It is not true that Germany violated the neutrality of Belgium,” and so on. Many of the greatest German scientists, like Felix Klein, Wilhelm Roentgen, and Max Planck, signed the declaration. Hilbert said, quite simply, that he was unable to verify to his exacting standards that the assertions in question were not true.

A year later, when the faculty at Göttingen balked at offering a position to the great algebraist Emmy Noether, arguing that students could not possibly be asked to learn mathematics from a woman, Hilbert responded: “I do not see how the sex of the candidate is an argument against her admission. We are a university, not a bathhouse.”

But reasoned analysis of politics has its limits. As an old man in the 1930s, Hilbert seemed quite unable to grasp what was happening to his home country as the Nazis consolidated their power. His first PhD student, Otto Blumenthal, visited Hilbert in Göttingen in 1938 to celebrate his seventy-sixth birthday. Blumenthal was a Christian but came from a Jewish family, and for that reason had been removed from his academic position at Aachen. (It was the same year that Abraham Wald, in German-occupied Austria, left for the United States.)

Constance Reid, in her biography of Hilbert, recounts the conversation at the birthday party:

“What subjects are you lecturing on this semester?” Hilbert asked.

“I do not lecture anymore,” Blumenthal gently reminded him.

“What do you mean, you do not lecture?”

“I am not allowed to lecture anymore.”

“But that is completely impossible! This cannot be done. Nobody has the right to dismiss a professor unless he has committed a crime. Why do you not apply for justice?”

When to use it

  • Analyzing a constitution or legal code for inconsistencies or loopholes that could be exploited.

  • Evaluating political statements or declarations for factual accuracy before endorsing them.

  • Applying axiomatic reasoning to design public policy frameworks with clear principles and deductions.

  • Teaching students about the applicability and limitations of logical methods in non-mathematical domains.

FROM THEORY TO EVERYDAY LIFE

In practice

01

Gödel's Constitutional Concern

During his U.S. citizenship test in 1948, Kurt Gödel discovered what he believed was a contradiction in the U.S. Constitution that could allow a dictatorship. He attempted to explain this to the examiner, but was cut off. Formal logical analysis can uncover potential flaws in political documents.

02

Hilbert's Refusal to Sign the 1914 Declaration

In 1914, many German scientists signed a declaration defending the kaiser's war, denying various allegations. Hilbert refused, stating he could not verify the truth of those denials to his exacting standards. This shows his commitment to logical consistency over political pressure.

03

Hilbert's Defense of Emmy Noether

When faculty objected to hiring Emmy Noether because she was a woman, Hilbert retorted, 'We are a university, not a bathhouse.' Hilbert applied reasoned analysis to sex discrimination.

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A MOMENT TO REFLECT

Put it to work.

  1. How might formal logical analysis help uncover hidden contradictions in political or legal systems? What are the risks of an overly formal approach?

  2. In the story of Hilbert and the 1914 declaration, what does the example teach us about the tension between intellectual honesty and political solidarity?

  3. Why might a brilliant logician like Hilbert be blind to the political realities of Nazi Germany? What does this say about the limits of pure reason in politics?

References

  1. Axiomatic Thought — David Hilbert (1918)
  2. Hilbert — Constance Reid

CONTINUE THE CONVERSATION

Source texts

  • How Not to Be Wrong The Power of Mathematical Thinking (Ellenberg, Jordan)
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