In posting on utilitarianism and consequentialism a while back, I meant to get on to some relevant implications, but got sidetracked into some interesting disputes with political and legal philosophers. There’s a lot I need to do to shore up my position on the issues raised, but blogging is nonlinear, so I’m going to jump straight to some conclusions, with the plan of filling in the gaps later.
My first observation is that sensible use of consequentialist reasoning requires that we evaluate decisions in terms of the outcomes that could be seen as possible when the decision was made (preferably with probabilities attached, but that’s not always feasible) rather than on the basis of the outcome that actually took place.
To give an example, let’s suppose, as is commonly claimed, that Reagan’s military buildup was designed to force the Soviet rulers to undertake a matching buildup, wrecking their economy and thereby hastening the downfall of Communism. Such a policy obviously entailed a somewhat higher risk that the arms race would lead to nuclear war between NATO and the Warsaw Pact. I’ll be conservative and make the increase in risk one percentage point over the decade or so of the buildup. And I’ll suppose that the arms race brought forward the collapse of Communism by a full decade.
Considered in advance, and with these assumptions, Reagan’s policy was clearly a bad one. A nuclear war would have killed hundreds of millions of people and even a one per cent chance of such a disaster was too terrible a price to pay for the near-certain benefit of an early end to Communism.
Note that, if you focus on actual consequences, you’ll almost always support gambles of this kind. On the assumptions above, there’s a 99 per cent chance that the policy will pay off, as it did.