Astral Codex Ten

A friend asked me to investigate the following mystery: why do 5-10% of skulls from 10,000 BC to 3,000 BC, all over the world, have holes in them?

The latest bugbear is “AI successionism”, the belief that AIs should succeed humans as rulers of Earth.

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[This is one of the finalists in the 2026 book review contest, written by an ACX reader who will remain anonymous until after voting is done.

By Meetups Czar Skyler: There are two laws of the ACX Meetup Czar.

AI companies like Anthropic and OpenAI have long mentioned the possibility that their products could be existentially dangerous, but this has recently crescendoed into even more dire warnings, including suggestions that we have to pace the frontier, ie co…

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[This is one of the finalists in the 2026 book review contest, written by an ACX reader who will remain anonymous until after voting is done.

In past election years, I’ve shared how I plan to vote in local elections.

A technician at a Siberian lab has died of yersinia infection aka plague.

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Dear Steven: Earlier this month, frustrated by some of your social media posts, I challenged you to a public debate on AI.

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This is a guest post by Drew Housman, whose review of Dominion earned finalist status in the 2024 ACX book review contest.

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[This is one of the finalists in the 2026 book review contest, written by an ACX reader who will remain anonymous until after voting is done.

Didn’t we just do this?

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Hi, this is Lars Doucet, author of the book review of Henry George’s Progress and Poverty that won the first ACX book review contest, as well as the three-part follow-up guest post series, “Does Georgism Work?”

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[This is one of the finalists in the 2026 book review contest, written by an ACX reader who will remain anonymous until after voting is done.

This is a guest post by ACX grantee Josh Morrison of 1DaySooner.

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On housing prices: The San Franciscans at this moment, living in their rag palaces, or renting them at figures that would have sounded possible in the Arabian Nights . . . seemed more like madmen than ever.

The Story So Far Mechanistic interpretability is the science of “reading an AI’s mind”.

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[This is one of the finalists in the 2026 book review contest, written by an ACX reader who will remain anonymous until after voting is done.

Twice a year, I try to advertise ACX meetups around the world.

I am Daniel Böttger1.

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[This is one of the finalists in the 2026 book review contest, written by an ACX reader who will remain anonymous until after voting is done.

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Each year, I post a reader survey.

[Original post: Why I’m Staying Out Of The Substack Religion Debate] Ben Smith writes: This post sure reads like participating in the object level debate, not just "writing a post about how I won't participate".

In early July, Cassie Pritchard argued on Twitter that liberalism had failed; it bet the farm on economic progress making people happier, but although it delivered impressive economic progress, happiness had failed to follow.

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[This is one of the finalists in the 2026 book review contest, written by an ACX reader who will remain anonymous until after voting is done.

There are ACX meetup groups in cities around the world.

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This is the weekly visible open thread.

[This is one of the finalists in the 2026 book review contest, written by an ACX reader who will remain anonymous until after voting is done.

[previously in series: 1, 2, 3, 4, 5, 6, 7, 8, 9] Paul Graham once said that every city sends a message.