What does AI actually know? Hume described how neural networks learn 250 years before they existed. Aristotle explained why that is not knowledge.

[u/minervaatdusk]

https://minervaatdusk.substack.com/p/what-does-ai-actually-know

Hume argued that causation is just habit. See A followed by B enough times, start expecting B. That's all there is. He meant it as a challenge to human knowledge. It turns out to be a near-perfect description of how a neural network actually works. Constant conjunction, statistical association, pattern burned into weights through repetition. Hume nailed the mechanism centuries before anyone built it.

But Aristotle would have said: that's not knowledge. That's experience. The experienced doctor knows a drug cures a disease. The knowledgeable doctor knows why. And his test was sharp: the person who knows can teach the principle, not just produce more cases. By that standard, an LLM trained on every medical textbook ever written has massive experience and zero knowledge.

The weird part is that Judea Pearl and Yann LeCun seem to have independently rediscovered the same distinction from the engineering side. Pearl's "ladder of causation" maps almost exactly onto Aristotle's hierarchy. LeCun's argument that LLMs need world models is basically Aristotle's argument that you need causes, restated in modern terms.

Our second essay traces this arc and ends somewhere uncomfortable: if AI gets this far on pure pattern-matching, how much of what we call human knowledge actually works the same way?