Begin with the principle:
- It is impermissible to harm others (other things being equal).
I intend 'harm' in a very broad sense. Certainly you harm someone if you physically injure them , but also if, without injuring them, you prevent them from doing something they would have preferred to do, or coerce them to choices they would rather not make. You may also think you do someone a harm if you wound their pride or disappoint them; if so , I won't quarrel with you here: count injured feelings in as well. Some readers may-- for sophisticated philosophical reasons-- feel uncomfortable with the word 'harm'. If you find (1) more obviously true if you replace 'harm' with 'make unhappy' or 'diminish the utility of' or 'interfere with' or 'act contrary to the long term rationally revealed interests of' ... feel free make the substitution. 1 You are reading me right if you construe (1) as an obvious truism.
Assuming we agree about (1), we turn to the question of what these other things are that that must be equal? In what circumstances is it permissible to harm another?
Self-defense is an obvious example. Other things being equal, if someone is physically attacking you, you are entitled to do them harm. How much harm is an interesting question. It is not a matter of strict proportionality. If the attacker just wants to cut off your arm to add to his collection you are not constrained to do no worse than amputate his. But if all he aims to do is push ahead of you in a ticket queue, disemboweling him might be excessive. Roughly speaking, it seems that if you are the victim of an attack, you are permitted to do your attacker only as much harm as is required to thwart the attack and, perhaps, a bit more to discourage its being renewed.
Details aside, "The Right of Self Defense" obviously means nothing if it does not include permission to do appropriate violence to your attacker.
My next question is this: does it mean anything more? Is there something more you must have -- something beyond the moral permission to forcefully defend yourself -- before you enjoy the right of self-defense in full?
I think it is clear that there is not. And I take this to show that having the right of self-defense is constituted by-- is nothing but-- the moral permissibility, ceteris paribus, of doing (appropriate) harm to those who attack you.
The view I am going to call "Retributive Ethics" is the doctrine that all rights are like this. It holds that all moral rights are merely provisos in the general prohibition against harming others and that what is morally impermissible is always and only the infliction of harms without right.
Retributivism is a reductive claim. If you like your philosophical theses to be framed as analyses2, you may take it as proposing a certain form of analysis of "morally impermissible", viz. :