The same moral paradox exists elsewhere. Consider prisons and capital punishment. Can a person believe in capital punishment while simultaneously believing condemned prisoners still have certain rights and that prisons should be humane places, even on death row? Even countries that have executions do not usually sanction the physical torture of prisoners condemned to death, in large part because such cruelty is repugnant and unnecessary. (Some may say capital punishment would count as repugnant and unnecessary too, of course. But the point stands.)
