I never said an AGI cannot know its own code, I said it cannot know both its own code AND its own truthfulness (while being truthful and satisfying certain othe

I never said an AGI cannot know its own code, I said it cannot know both its own code AND its own truthfulness (while being truthful and satisfying certain other idealized assumptions). As for why this is the case: it's not an assumption, but rather, a theorem, one which has been known for a long time. Here's an extremely oversimplified proof: suppose Turing machine #500 encodes an AGI X and that AGI X knows "My knowledge is truthful" and "I am encoded by Turing machine #500". Using Goedel's diagonal lemma, there is a sentence phi, in the language of Peano arithmetic, which expresses "Turing machine #500 knows the negation of phi". Since X knows himself to be Turing machine #500 and X knows himself to be truthful, X should be able to infer that phi is false (because if phi were true, then Turing machine #500 would know the negation of phi, so (since Turing machine #500 is truthful), phi would be false, a contradiction). So X knows that that phi is false. But phi is synonymous with the assertion that X knows phi is false---so, since we have shown "X knows phi is false", we have in fact shown phi is true. Absurd. Our only escape from the paradox is to acknowledge that X cannot know "I am truthful" and "I am Turing machine #500" simultaneously (and also really be truthful and satisfy idealizing assumptions that allow X to make the above inferences). You're right that I keep using words informally, because this is hacker news and not a logic journal. If you want to see things spelled out in gruesome detail (warning: math), you can read here: https://philpapers.org/archive/ALEMTI-2.pdf https://philpapers.org/archive/ALEMTI-2.pdf