A lame argument.

I thought of this while I was in the shower this morning.

I take two principles to be generally plausible. 1) If a moral intuition leads to a judgment that is anomalous, there is good reason for revising that intuition and judgment. 2) Most deontologists claim that there is some threshold of harm where the doing/allowing distinction gives out.

Furthermore,

(3) Assume that the threshold is 10,000 lives.

Thus,

(4) it is illegitimate to kill someone except to save 10,000 lives or more.

But given (1), we have reason to reject (4). Because in this case, the intuition that leads us to the judgment that we should not kill one to save fewer than ten thousand is anomalous. Why? Because that intuition is only applicable in a finite number of cases, i.e., cases in which the number of deaths prevented by one killing run up to 9,999. But the alternative intuition, in which killing is acceptable is applicable in a transfinite number of cases. Thus, we should revise (3), and suggest that in all cases, killing one is acceptable in preventing harm. Any finite number will be anomalous.

This argument is pretty lame, but that's what happens when you wake up at 6:45am.