A few years ago, we developed the concept of “role-reversibility” in AI governance: the idea that it matters whether a party exercising judgment is reciprocally vulnerable to the effects of judgment. This idea, we argued, supplies a deontic reason to maintain certain spheres of human judgment even if (or when) truly intelligent machines become demonstrably superior in every utilitarian sense. While computer science remains far from that holy grail, generative AI is raging through systems as diverse as healthcare, finance, advertising, law, and academe, making it imperative to further shore up our claim. We do so by situating role-reversibility within the long arc of criminal justice philosophy, from Anaximander to Aristotle to Seneca. Simply put, role-reversibility facilitates mercy. And mercy is both (1) central to the operation of a humane legal system and (2) impossible, even in principle, to automate.