Perhaps a better thought experiment, then, is to offer Gary the chance to travel back in time and feed his 2-year-old self the pill. Or, if you dislike time machines in your thought experiments, we can simply ask Gary whether or not he now would have wanted his parents to have given him the pill when he was a child. Presumably the answer will still be no.
If timetravel is to be considered then we must emphasize that when we say ‘current preferences’ we do not mean “preferences at time Time.now, whatever we can make those preferences be” but rather “I want things X, Y, Z to happen, regardless of the state of the atoms that make up me at this or any other time.” Changing yourself to not want X, Y or Z will make X, Y and Z less likely to happen so you don’t want to do that.
Perhaps a better thought experiment, then, is to offer Gary the chance to travel back in time and feed his 2-year-old self the pill. Or, if you dislike time machines in your thought experiments, we can simply ask Gary whether or not he now would have wanted his parents to have given him the pill when he was a child. Presumably the answer will still be no.
If timetravel is to be considered then we must emphasize that when we say ‘current preferences’ we do not mean “preferences at time Time.now, whatever we can make those preferences be” but rather “I want things X, Y, Z to happen, regardless of the state of the atoms that make up me at this or any other time.” Changing yourself to not want X, Y or Z will make X, Y and Z less likely to happen so you don’t want to do that.