“Infinite ethics and UDASSA” by David Matolcsi

Reading the first post of the sequence (Probabilities are not the right concept) is recommended but not required for understanding this post.[1] Infinite ethics Once you start looking at infinities, all ethical systems get confusing. Intuitively, it's good to plant an apple tree. But if the universe already has infinitely many apple trees, why bother? Infinity plus one is still infinity. And there are the classic paradoxes: an infinite grid of houses, each with three happy people and one unhappy person, seems better than the reverse. But you can rearrange people between the two configurations, since both the happy and unhappy populations are infinite. Does this mean you can make the world better just by shuffling people around? These questions matter because our universe is quite likely infinite in one way or another. The world very well might be spatially infinite. The many-worlds interpretation of quantum mechanics is pretty popular, and some versions of it imply infinite worlds, though boundaries are not well-defined. And I have a fondness for the Tegmark-IV multiverse theory where every computable mathematical structure exists in a real sense. And even if you only give 1% credence to the universe being infinite in some [...] ---Outline:(00:18) Infinite ethics(03:08) Decision theory(04:32) Decisions as a mortal(07:53) Decisions when we become wiser(09:03) An aside on simulations(10:49) Attempted synthesis: Realist UDASSA(13:23) Benefits of UDASSA(13:31) Benefit 1 - Boltzmann brains(14:51) Benefit 2 - Dust theory(15:45) Benefit 3 - Defense against Pascal's mugging(16:46) Problems of UDASSA(17:05) Problem 1 - Assuming pseudo-randomness(18:34) Resolution - Solomonoff over distributions(21:54) Problem 2 - The inter-universal obelisk race(24:17) Problem 3 - World-summoning by writing(26:19) Problem 4 - I just don't believe in reality fluid(30:55) Attempted synthesis: Non-Realist UDASSA(31:51) Problems with non-realist UDASSA The original text contained 21 footnotes which were omitted from this narration. --- First published: May 28th, 2026 Source: https://www.lesswrong.com/posts/zvqodicK8q2SNAZkd/infinite-ethics-and-udassa --- Narrated by TYPE III AUDIO.