Shewing the fly

Fairly soon after I published my earlier post on the argument, I realised that instead of criticising Caplan’s argument, I was actually arguing for his position. So, here is a new informal argument for pacifism, based on his own and my failed critique:

1. The short run costs of war are very high (innocent people are killed)
2. The long run benefits and costs of a war are subject to extreme Knightian uncertainty
3. Where the benefits or costs of a decision are subject to extreme Knightian uncertainty, they ought to be excluded from rational calculation (essentially the point I made in my last post)
4. Therefore, we ought to exclude the potential long-term benefits and costs of war from rational calculation (my friend David’s comment on my last post explains this premise nicely)
5. Therefore, as the category of reasons usually given for war (the achievement of a long-run benefit) have to be excluded from rational calculation, we ought not to go to war in those cases

You could argue in some cases that there are short-term reasons to go to war that are not subject to Knightian uncertainty and that therefore the pacifism one can conclude does not apply to all cases. Fair enough, I’m not going to argue against war in immediate self-defence (although I could, and Caplan makes a few points here about the Warsaw Ghetto Uprising). But given that a lot of justifications for war involve the desire to fulfil long-term strategic or moral objectives (see interventionism, liberal) Caplan’s argument mitigates very strongly in the direction of not taking deliberate action that we can foresee will lead to our killing of innocent people.