Sunday, May 9, 2010

Is the Principle of Double Effect the sum total of normative ethics?

The Principle of Double Effect (PDE) is often stated in something like this form: An action that is foreseen to have an evil effect (maybe better: an effect that is a basic evil—I shall not worry about this) E is permissible if:

  1. the action is not intrinsically wrong
  2. a good is intended
  3. E is not intended, either as a means or as an end
  4. E is not disproportionate to the intended good.
This sort of formulation is obviously incorrect. After all, conditions (1)-(4) which are supposed to be sufficient for permissibility are compatible with the action also being intended to have another evil effect E*. That particular problem is easily fixed. We just say that an action that is foreseen to have at least one evil effect is permissible if:
  1. the action is not intrinsically wrong
  2. at least one good is intended
  3. no evil is intended, either as a means or as an end
  4. the foreseen evils are not disproportionate to the intended good or goods.
This is better.

Now, observe two interesting facts. First, if an action that is foreseen to have at least one evil effect and that satisfies (5)-(8) is permissible, then a fortiori an action that is not foreseen to have any evil effects and that satisfies (5)-(8) should also be permissible. (It would be really, really weird if an action would become permissible as soon as one noticed some tiny evil side-effect.) So, in fact, the PDE gives a set of sufficient conditions for permissibility. Second, it is clear that (5) and (8) are necessary conditions for permissibility. Moreover, if (7) weren't a necessary condition for permissibility, there would be little need for a PDE. Finally, it is plausible that an action that aims at no good is a perversion of will, and hence on Natural Law grounds (6) will be necessary. Moreover, it may even be the case that every action has to intend at least one good in order to be an action, and hence (6) may be trivial.

If so, then if (5)-(8) are the right conditions to put in the PDE, they are a complete account of permissibility. This makes the PDE not just something peripheral to a deontic ethics, an epicycle for handling some wartime and medical cases, but in fact it makes the PDE be all of normative ethics.

However, as tomorrow's post will show, a PDE like (5)-(8) is not the right way to think of the insights embodied in double effect reasoning (to use Cavanaugh's phrase).


Heath White said...

Well, you might need a little window-dressing to flesh out the terms "intrinsically wrong", "good", "evil," "intended", and "disproportionate." But that shouldn't be hard....

(I'm being a little facetious.)

Mike Almeida said...

There is a genuine worry with the formulation, I think, since the foreseen evils might not be the only evils forthcoming as a result of E. The principle makes the metaphysical claim (that E is permissible) depend on the epistemology of foreseeing evils. So the principle seems embarrassed by cases in which an extraordiarily serious evil is the effect of E and is overlooked. Why would an epistemological error make an action permissible? Why would even a non-culpable epistemological error make an action permissible? What is getting conflated is the permissibility of the action and the blamelessness of the agent. One way to repair this is to idealize the agent epistemologically. But that's ot easy to do, as ideal observer theories attest. Another way is just to modify (8) to "neither foreseen nor unforseen evils are ...."

Alexander R Pruss said...


If you like, you can modify (8) to count as part of the proportionality calculus not only the consequences that are foreseen but also those that should have been foreseen. Or even all consequences. It doesn't affect my main point.

Mike Almeida said...

Well, it does affect the point that you've offered a general theory of permissibility. Even if you restrict (8) to all evils that should have been foreseen, you don't have a tenable theory of permissibility. You still have permissibility epistemically conditioned. It can't be right that A is permissible only if I do not know about it's evil effect E (even if I could not be expected to know about it). In that later case I've done something impermissible, but I'm less (or perhaps not at all) blameworthy.

But even if we set aside this worry, surely the conditions in (5) -(8) cannot be sufficient for permissiblity of an action. It cannot be true, for instance, that if I stab you with a pencil intending the good of warding off evil demons, and only foreseeing the pain I cause (not intending it), and being possessed by demons is worse that being stabbed with a pencil, then I've done something permissible. It's just bizarre to think that a series of false beliefs about demon possession and it's relation to pencil stabbings, can make an action of stabbing someone with a pencil permissible.