New information is gained every day there isn't a ritual self-sacrifice. Start with the simplest scenario that his words imply and work up every day from there.

New information is gained every day there isn't a ritual self-sacrifice. Start with the simplest scenario that his words imply and work up every day from there. One blue eyed person could look around, see only brown (or other color) eyes, and figure out they must have been the one talked about, right? Boom, gone. Two blue eyed people would look around and see the other blue eyed person. However when the conditions for "one blue eyed person" aren't met, they would see the next day that there are 998 non-blue-eyed people and reason that the other blue eyed person must have seen a blue eyed person and it would have to be them. Boom. Gone. Three blue eyed people would look around and see two other blue eyed people. After the first two days they'd realize that since the conditions of the 2 blue eyed person scenario weren't met, there are 3 blue eyed people, and since they can see 997 other-eyed people, they must be the third in that scenario. Boom. Gone. And so on and so on.