On a generalization of Double Effect

Traditional formulations of the Principle of Double Effect deal with things that are said to have absolute prohibitions against them, like killing the innocent: such things must never be intended, but sometimes may be produced as a side-effect.

Partly to generalize the traditional formulation, and partly to move beyond strict deontology, contemporary thinkers sometimes modify Double Effect to be some principle like:

1. It is worse, or harder to justify, to intentionally cause harm than to do so merely foreseeably.

While (1) sounds plausible, there is a family of cases where intentionally causing harm is permitted but doing so unintentionally is not. To punish someone, you need to intend a harm (but maybe not an all-things-considered harm) to them. But there are cases where a harsh treatment is only permissible as a punishment. In some cases where someone has committed a serious crime and deserves to be imprisoned, and yet the imprisonment is not necessary to protect society (e.g., because the criminal has for other reasons—say, a physical injury—become incapable of repeating the crimes), then the imprisonment can be justified as punishment, but not otherwise. In those cases, the harm is permitted only if it is intended.

It still seems that it tends to be the case that intentional harm is harder to justify than merely foreseen harm.