"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?
"Following your heart and not your head - refusing to multiply - has also wrought plenty of havoc on the world, historically speaking. It's a questionable assertion (to say the least) that condoning irrationality has less damaging side effects than condoning torture."
I'm not really convinced that multiplication of the dust-speck effect is relevant. Subjective experience is restricted to individuals, not collectives. To me, this specific exercise reduces to a simpler question: Would it be better (more ethical) to torture individual A for 50 years, or inflict a dust speck on individual B?
If the goal is to be a utilitarian ethicist with the well-being of humanity as your highest priority; then something may be wrong with your model when the vast majority of humans would choose the option that you wouldn't. (As I suspect they would). Utility isn't all that matters to most people. Is utilitarianism the only "real" ethics?
My criticisms can sometimes come across the wrong way. (And I know that you actually do care about humanity, Eli.) I don't mean to judge here, just strongly disagree. Not that I retract what I wrote; I don't.