The moral equality of combatants
The moral equality of combatants

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The moral equality of combatants

The voluntariness argument

For the sake of argument, let us concede that there is a series of questions that combatants can ask, and accept also that they should ask themselves these questions. They ask themselves these questions, and then they make a judgement. They choose to join up, or, if they have joined up, they choose to remain in the military rather than desert. McMahan’s account suggests that joining up does not free me of moral responsibilities: if my cause is unjust, I act unjustly in attempting to further it. What, then, does change? What is it for me to enlist in the military? One way of describing what it is that I do when I join the military is to say that I consent to putting myself in the firing line. So, in a way, I consent to be targeted. If I do this, and the people I fight also do this, then are we not, in an important sense, morally equal?

The American philosopher Thomas Hurka has developed this point into an argument that defends the moral equality of combatants. The argument turns on our being free to give up our rights. For example, I have the right to lie in bed all day if I want to. However, if I voluntarily enter into a contract with you – say, I accept your offer of a job – then I lose that right. Indeed, you have the right to insist that I get out of bed and turn up for work.

Activity 8

Read Reading 3 ‘Hurka on the moral equality of soldiers’ at the end of this free course . This is an extract from Hurka’s article ‘Liability and just cause’, which appeared in the journal Ethics and International Affairs . Once you have read the extract, answer the questions below. (Hurka uses the word ‘inalienable’ in the extract. To claim that a right is ‘inalienable’ is to claim that it cannot be given up.)

Link to Reading 3

  1. What exactly does Hurka think happens to your right not to be killed when you join the army?
  2. What two objections to this view does he consider?


  1. Hurka’s view is that combatants waive, temporarily, their right not to be killed when they join the army.
  2. The two objections that Hurka identifies are:
    • i.That the right not to be killed is inalienable.
    • ii. That just combatants can fight proportionally and unjust combatants cannot.

Hurka needs to find ways to overcome these objections if his argument is to succeed. First, let us consider his attempts to reply to the first objection (that the right not to be killed is inalienable). He begins by describing a case of a contract in which A offers B $100,000 per year for 10 years in return for the right to kill B after that time. Hurka claims that ‘many will say’ that A does not get the right to kill B; B cannot trade his life for money, as the right not to be killed is inalienable. Of course, if volunteering for the military is analogous to this case, then combatants too will not be able to forgo their right not to be killed, and Hurka’s argument will fail.

I shall list each of the replies Hurka makes. You will need to go back to the reading to ensure that you have grasped them.

  1. The right to be killed is alienable (so there is no objection anyway).
  2. The case of the military is not analogous to the contract case, because combatants only give up their liberty rights. To have a liberty right is to have a right to do something (that is, one is not obliged not to do it). To have a claim right is to have a liberty right and also to have a claim over someone else (perhaps a duty to help me exercise that right).
  3. The case of the military is not analogous to the contract case, because it is symmetrical and the contract case is not.
  4. The case of the military is not analogous to the contract case, because it is revocable and the contract case is not.
  5. The case of the military is not analogous to the contract case, because it is a waiving of a right and not an alienating of a right.

Hurka claims that, taken together, these make the military not analogous to the contract case (which would be problematic) but rather analogous to the boxing case (which is not problematic). You should consider each of these distinctions, and whether they make a morally relevant difference in the case of the contract.

Activity 9

What is Hurka’s response to the second objection?


Broadly, he accepts it. In wars fought only between combatants there is moral equality. However, in most wars civilians will also be harmed. For just combatants this is sometimes proportionate, for unjust combatants it is never proportionate.

Hurka sums up his views as follows:

If soldiers on both sides have surrendered their right not to be killed to all enemy soldiers in all future wars, then with respect to each other they are moral equals, each permitted to kill their enemy and liable to be killed by them. The two sides are not completely morally equal, since in most wars just combatants can fight proportionally while unjust ones cannot. But insofar as they target each other, both act permissibly and neither’s acts are wrong. In that important respect they are moral equals.

So Hurka defends the idea of the moral equality of combatants, but with a different central argument from that of Walzer. Before any war has begun, combatants have voluntarily waived their right not to be killed: they have made themselves liable to attack by joining up.

How might McMahan respond? McMahan argued that material non-innocence was not enough to establish the moral equality of combatants, we also had to look at the broader picture. If someone assaults me, and I resist, that does not make us morally equal in the damage we inflict upon each other. We can try to fit Hurka’s argument into this analogy. Hurka argues that if I volunteer to get into a fight then I give up my right not to be hit (that is part of what volunteering to get into a fight is).

Is it always true that in volunteering to fight one gives up the right not to be harmed? This certainly seems true for the boxer. However, if I choose to defend my home against a hostile invading army, does that give the hostile army the right to kill me? What do you think?


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