"What's the worst that can happen?" goes the optimistic saying. It's probably a bad question to ask anyone with a creative imagination. Let's consider the problem on an individual level: it's not really the worst that can happen, but would nonetheless be fairly bad, if you were horribly tortured for a number of years. This is one of the worse things that can realistically happen to one person in today's world.
What's the least bad, bad thing that can happen? Well, suppose a dust speck floated into your eye and irritated it just a little, for a fraction of a second, barely enough to make you notice before you blink and wipe away the dust speck.
For our next ingredient, we need a large number. Let's use 3^^^3, written in Knuth's up-arrow notation:
- 3^3 = 27.
- 3^^3 = (3^(3^3)) = 3^27 = 7625597484987.
- 3^^^3 = (3^^(3^^3)) = 3^^7625597484987 = (3^(3^(3^(... 7625597484987 times ...)))).
3^^^3 is an exponential tower of 3s which is 7,625,597,484,987 layers tall. You start with 1; raise 3 to the power of 1 to get 3; raise 3 to the power of 3 to get 27; raise 3 to the power of 27 to get 7625597484987; raise 3 to the power of 7625597484987 to get a number much larger than the number of atoms in the universe, but which could still be written down in base 10, on 100 square kilometers of paper; then raise 3 to that power; and continue until you've exponentiated 7625597484987 times. That's 3^^^3. It's the smallest simple inconceivably huge number I know.
Now here's the moral dilemma. If neither event is going to happen to you personally, but you still had to choose one or the other:
Would you prefer that one person be horribly tortured for fifty years without hope or rest, or that 3^^^3 people get dust specks in their eyes?
I think the answer is obvious. How about you?
No. One of those actions, or something different, happens if I take no action. Assuming that neither the one person nor the 3^^^3 people have consented to allow me to harm them, I must choose the course of action by which I harm nobody, and the abstract force harms people.
If you instead offer me the choice where I prevent the harm (and that the 3^^^3+1 people all consent to allow me to do so), then I choose to prevent the torture.
My maximal expected utility is one in which there is a universe in which I have taken zero additional actions without the consent of every other party involved. With that satisfied, I seek to maximize my own happiness. It would make me happier to prevent a significant harm than to prevent an insignificant harm, and both would be preferable to preventing no harm, all other things being equal.
If the people in question consented to the treatment, then the decision is amoral, and I would choose to inflict the insignificant harm.
From a strict utility perspective, if you describe the value the torture as -1, do you describe the value of the speck of dust in one person's eye as less than -1/(3^^^3)? There is some epsilon for which it is preferable to have harm of epsilon done to any real number of people than to have harm of -1 done to one person. Admitting that does not prohibit you from comparing epsilons, either.