I complained a while ago about the imprecision, if not downright impossibility, in determining “proportionality” in cases where innocents are foreseeably, but not directly, killed in warfare.

The usual way of formulating the proportionality criterion is to say something like the evil of any innocent deaths must be outweighed by the good accomplished by the act which results in those deaths.

A different formulation is offered by Catholic moral theologian Germain Grisez. We might call this the “Golden Rule” of proportionality since it appeals to doing as you would be done by.

In this piece, published shortly after 9/11, Grisez offers this formulation:

[W]hen stopping terrorism requires the use of force against the activities of terrorists or of people complicit in their terrorism, any foreseeable damage to innocents (that is, people not engaged in those activities) must be no more than what those using the force would think it fair to accept if the innocents were their own friendly associates.

This approach neatly sidesteps the problem of “weighing” incommensurable values (e.g. human lives vs. freedom or security), a problem that bedevils most utilitarian accounts.

However, this principle seems to have the unwelcome implication that the morally worse one’s leadership is, the greater number of innocent deaths it’s permitted to inflict. For instance, someone like Saddam Hussein, who demonstrated little regard for his subjects, presumably wouldn’t have much of a problem sacrificing a large number of Iraqi citizens to further his goals. So, by Grisez’s principle it seems that Saddam would be justified in inflicting more collateral damage on an enemy’s civilians than a more humanisitc leader!

This could be seen as just a specific instance of the general problem of applying the Golden Rule. “Do as you would be done by” only makes sense as a moral principle if you already posses a sound understanding of what it’s proper to want done to yourself.