Subjecthood necessary for punishment
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Harm can constitute punishment only if the harmed is subject to the law.
Lastly, harm inflicted upon one that is a declared enemy falls not under the name of punishment: because seeing they were either never subject to the law, and therefore cannot transgress it; or having been subject to it, and professing to be no longer so, by consequence deny they can transgress it, all the harms that can be done them must be taken as acts of hostility. But in declared hostility all infliction of evil is lawful. From whence it followeth that if a subject shall by fact or word wittingly and deliberately deny the authority of the representative of the Commonwealth (whatsoever penalty hath been formerly ordained for treason), he may lawfully be made to suffer whatsoever the representative will: for in denying subjection, he denies such punishment as by the law hath been ordained, and therefore suffers as an enemy of the Commonwealth; that is, according to the will of the representative. For the punishments set down in the law are to subjects, not to enemies; such as are they that, having been by their own act subjects, deliberately revolting, deny the sovereign power.
Hobbes, Lev XXVII 13