Very happy to introduce our next Featured Philosopher: Jonathan Quong. His fear of PEA Soup Overlords warms the heart. Here now Jonathan:
I’m working on a book, The Morality of Defensive Force, and in this post I’ll provide a brief description of one of the ideas from the book.
Most people who work on the morality of defensive force agree that it’s wrong to use defensive force when doing so is unnecessary. For example, suppose you can avert a wrongful aggressor’s attack in one of two ways: you can shoot and kill the aggressor, or you can render him unconscious with some knockout gas that will have no lasting harmful effects. Killing the aggressor is wrong because it isn’t necessary.
But why is it wrong to use unnecessary defensive force? You might think unnecessary defensive force is wrong because it involves the imposition of gratuitous harm, that is, the imposition of harm for no positive moral reason. But this isn’t true. Suppose you can avert the wrongful aggressor’s threat either by killing him, or else by jumping to safety, but you will suffer a tiny scratch on your hand if you jump. Shooting the aggressor is not gratuitous—doing so helps you avoid suffering a minor scratch. But shooting the aggressor is, I think, still clearly unnecessary.
Some thus argue that the necessity condition requires a kind of moral weighting of the defender’s options. We weigh all the harms that would be incurred by anyone if the defender chooses option 1, and compare this moral weighting to all the other available options, while also discounting harms that any wrongful aggressors might suffer relative to harms suffered by the defender or innocent bystanders. The necessity condition then directs the defender to choose the option with the lowest morally weighted harm, or the lowest expected morally weighted harm. Seth Lazar and Jeff McMahan have, independently, defended versions of this view of necessity. The necessity condition thus ends up looking an awful lot like another constraint on the permissible use of force, wide proportionality, which is concerned with whether a harmful act is justified once all the harmful effects of the act are taken into account.
But here’s the sort of case that illustrates why we need a different conception of the necessity condition:
Grenade: Albert is wrongfully threatening to seriously injure you. You have only two options: (i) allow him to wrongfully injure you, or (ii) throw a grenade that will cause Albert roughly equivalent injuries to those he is threatening to impose on you, thus leaving you safe, but the grenade will also kill six innocent bystanders.
In this case, the morally weighted harm in option (i) is far less than the morally weighted harm in option (ii). But it’s not wrong to throw the grenade because it’s unnecessary. Rather, it’s wrong to throw the grenade because doing so is disproportionate: it is not proportionate to kill six innocent people to avoid suffering serious injuries. If you threw the grenade, it would be very odd for Albert to complain that you used unnecessary defensive force against him. The bystanders are the ones who can demand that you refrain from throwing the grenade, not Albert.
I think the necessity condition should identify a complaint that is distinctive to the aggressor, which takes roughly the following form: “you owed it to meto suffer x amount of harm to ensure that I didn’t suffer y amount of harm”. There is a widely accepted moral right that has this structure: the right to be rescued when others can do so at reasonable cost. I argue that this right provides the underlying explanation for the necessity condition. Unnecessary defensive force is wrong because the defender could save the aggressor from some amount of harm at reasonable cost. Of course what’s unusual is that the defender can save the aggressor from harm that she herself might otherwise impose. This strikes some people as an important difference; it shows that the right to be rescued can’t really explain the necessity condition. But I argue that this isn’t a relevant difference—what matters is whether the defender (or anyone else) can bear a reasonable cost to ensure the aggressor doesn’t suffer some larger harm. I call this the RESCUE conception of the necessity condition.
This conception has several advantages. First, it shows why the necessity constraint gives rise to a demand that aggressors in particular can make of defensive agents.
Second, because it construes the necessity condition as giving rise to interpersonal moral demands, it yields better results in cases that have a certain temporal structure. These are cases where the defensive agent correctly predicts that if she performs some permissible act when she could easily refrain from doing so (e.g. wearing a short skirt, or confronting a partner about unpaid child support), an aggressor will initiate a wrongful attack that the defensive agent will then only be able to repel by imposing significant harm on the aggressor. If the necessity constraint requires us simply to balance the morally weighted harm associated with each of the defender’s options, then the defender would violate the necessity condition by performing the permissible act and then using proportionate defensive force. The rescue conception of the constraint doesn’t have this implication. Borrowing an idea developed by Jerry Cohen, I argue that where an interpersonal moral demand depends on a premise about a future empirical fact, and the person making the demand is the one who will make the empirical premise true, then the demander must be able to justify making the empirical premise true for the demand to be valid.
This gets things right. Abusive men, for example, cannot demand that their partners refrain from performing permissible acts by pointing out that they will become violent if their partners do these permissible things. Only if we construe the necessity condition as an interpersonal moral demand, one that has to pass the test described above, will we get the correct results in cases like this.
I have lots of other things to say about defensive force, but I’ve exceeded my word limit for this post, and I don’t want to anger the Pea Soup Overlords!