Eliezer’s question for Paul is not particularly subtle, so I presume he won’t mind if I give away where it is leading. If Paul says yes, there is some number of dust specks which add up to a toe stubbing, then Eliezer can ask if there is some number of toe stubbings that add up to a nipple piercing. If he says yes to this, he will ultimately have to admit that there is some number of dust specks which add up to 50 years of torture.
Rather than actually going down this road, however, perhaps it would be as well if those who wish to say that the dust specks are always preferable to the torture should the following facts:
1) Some people have a very good imagination. I could personally think of at least 100 gradations between a dust speck and a toe stubbing, 100 more between the toe stubbing and the nipple piercing, and as many as you like between the nipple piercing and the 50 years of torture.
2) Arguing about where to say no, the lesser pain can never add up to the slightly greater pain, would look a lot like creationists arguing about which transitional fossils are merely ape-like humans, and which are merely human-like apes. There is a point in the transitional fossils where the fossil is so intermediate that 50% of the creationists say that it is human, and 50% that it is an ape. Likewise, there will be a point where 50% of the Speckists say that dust specks can add up to this intermediate pain, but the intermediate pain can’t add up to torture, and the other 50% will say that the intermediate pain can add up to torture, but the specks can’t add up the intermediate pain. Do you really want to go down this path?
3) Is your intuition about the specks being preferable to the torture really greater than the intuition you violate by positing such an absolute division? Suppose we go down the path mentioned above, and at some point you say that specks can add up to pain X, but not to pain X+.00001 (a representation of the minute degree of greater pain in the next step if we choose a fine enough division). Do you really want to say that you prefer that a trillion persons (or a google, or a googleplex, etc) than that one person suffer pain X+.00001?
While writing this, Paul just answered no, the specks never add up to a toe stub. This actually suggests that he rounds down the speck to nothing; you don’t even notice it. Remember however that originally Eliezer posited that you feel the irritation for a fraction of a second. So there is some pain there. However, Paul’s answer to this question is simply a step down the path laid out above. I would like to see his answer to the above. Remember the (minimally) 100 gradations between the dust speck and the toe stub.
I agree that as you defined the problems, both have problems. But I don’t agree that the problems are equal, for the reason stated earlier. Suppose someone says that the boundary is that 1,526,216,123,000,252 dust specks is exactly equal to 50 years of torture (in fact, it’s likely to be some relatively low number like this rather than anything like a googleplex.) It is true that proving this would be a problem. But it is no particular problem that 1,526,216,123,000,251 dust specks would be preferable to the torture, while the torture would be preferable to 1,526,123,000,253 dust specks would be worse than the torture: the point is that the torture would differ from each of these values by an extremely tiny amount.
But suppose someone defines a qualitative boundary: 1,525,123 degrees of pain (given some sort of measure) has an intrinsically worse quality from 1,525,122 degrees, such that no amount of the latter can ever add up to the former. It seems to me that there is a problem which doesn’t exist in the other case, namely that for a trillion people to suffer pain of 1,525,122 degrees for a trillion years is said to be preferable to one person suffering pain of 1,525,123 degrees for one year.
In other words: both positions have difficult to find boundaries, but one directly contradicts intuition in a way the other does not.