The doctrine of the image of God is often regarded as grounding human dignity in something permanent and unchanging that transcends our attitudes and behaviors. Yet we persistently encounter the argument that particular human individuals or groups have acted so as to forfeit their moral standing as fellow humans. They are bestialized, categorized as non-human animals, lifting ordinary restraints on punishment. I examine the logic of this argument in John Locke, Thomas Aquinas, and contemporary felony disenfranchisement, showing how it involves slippage between the unobjectionable notion that specific rights may in particular circumstances be forfeited, and the deeply troubling claim that one’s moral standing as human can as such be forfeited. I argue that an apparently similar rhetoric of dehumanization employed by Frederick Douglass, in contrast, refrains from stripping the opponent of moral considerability.