Phi202

Natural law and rules of conduct - the principle of double effect

Recall: Natural law theory forbids intentionally committing acts that go against the basic human goods, and also holds that you fully intend, at least typically, the means you have knowingly employed to a given end.

" he who wills the ends wills the means " (that he used to achieve the end)

e.g. if you steal in order to fund a relief effort that saves lives, you can plausibly be held to intend not just the good ends but also the theft, however regretfully you may have performed it and even if you would have chosen some other means had it been available.

You are not, however, typically deemed to intend mere side-effects of achieving the ends (i.e outcomes that all short of being means).

The difference between an outcome of your act that is a side-effect of achieving the ultimate end and an outcome that is a means of achieving the end. A means causes the ultimately desired outcome, while a side-affect just accompanies the ultimately desired outcome.

Committing acts that involve a regretted means to a good end that goes against basic good is forbidden, because the means typically counts as intended.
Committing acts that involve a regretted and foreseen side-affect that goes against a basic good is sometimes permitted, because the side-effect typically doesn't count as intended.

E.g. Suppose it is a good ultimately desired end to rid Tasmania of its Viking overlords. It is not permitted to kill Viking civilians as a means of forcing them out. It can be, however, permitted to wage war that you know will kill some civilians as a side-affect.

Note that even if the civilian deaths are a side-effect and not a means, the action may still be forbidden if certain further conditions aren't met.

Full statement:

If (i) the ulatimate goal is good or at least indifferent

i.e doesn't go against a basic good.

(ii) if the bad effect in question is not intended

(iii) if the bad effect is not (intended as) a means to the good goal

(iv) the good result is proportionate to the to (i.e outweighs) the bad result

then the act will be (typically) permitted, even if the bad result is foreseen.