John Holbo over at Crooked Timber:
OK, let stop right there and back up. For those of you who aren’t academic philosophers: Rawls has two basic principles of justice, and the difference principle is one half of the second. It says that social and economic inequalities are permissible only to the extent that they benefit the least well off, relative to a situation in which the inequalities would be eliminated. If I have $10 and you only have $1, this is ‘just’ if any attempt to eliminate the inequality would leave you holding less than $1. Maybe we shift to a position in which I have only 99 cents, and you have 99 cents, and the rest of it goes wherever money goes when it dies. We are equal, but you are actually worse off, absolutely. Rawls says it isn’t necessary to get all drastically Harrison Bergeron, like that. Justice doesn’t demand it. Turning the point around: I can’t permissibly (justly) move from $10 to $11, widening the gap, unless the effect of this trickles down to you to the tune of $1.01 or more. But if you get that extra penny, my extra dollar is acquired consistent with the difference principle…
Now, Moore’s paradox (G.E. Moore, that is). ‘It’s raining, but I don’t believe it’. For any given individual – let’s call him Johnny, at a rainy bus stop – it can be true both that it is raining, and that he doesn’t believe it’s raining. (More denialism about various possibilities of direct trickle-down, I suppose.) But Johnny cannot sincerely (sanely), first-personally avow this potentially true statement. Mild logical curiosity, then. There are possibly true statements that one cannot sincerely (sanely) assert.
Now justice. Cohen is saying that, oddly, lots of individuals won’t be able to avow the difference principle. Not that it is false. It might be true, but they can’t coherently, sincerely avow its truth. Why not? Because they are like Johnny at the bus stop with $10 in pocket, next to someone with only $1. That’s all it takes.