"You are looking for an agent who is capable of choosing The Highest Number" - the agent wants to maximise utility, not to pick the highest number for its own sake, so that is misrepresenting my position. If you want to taboo utility, let's use the word "lives saved" instead. Anyway, you say "Therefore this agent (the perfect life maximising agent) can not exist", which is exactly what I was concluding. Concluding the exact same thing as I concluded, supports my argument, it doesn't contradict it like you seem to think it does.

"Alternately, letting "utility" back in, in a universe of finite time, matter, and energy, there does exist a maximum finite utility" - my argument is that there does not exist perfect rationality within the imagined infinite universe. I said nothing about the actual, existing universe.