One might then make an argument about the decision question that goes like this: Before I swore this oath, my probability of going to a tropical island was very low. After, it was very high. Since I really like tropical islands, this is a great idea. In a nutshell, I have increased my expected utility by making this oath.
If it is indeed in your power to swear and execute such an oath, then “I will make an oath to simulate this event and make such-and-such changes” is a legitimate event that would impact any probability calculation. Before swearing the oath, there was still the probability of you swearing it in the future and executing it.
The probability of going to a tropical island given that the oath was made is likely higher than it was before the oath was made, but the only way it would be significantly higher is if there was a very low probability of the oath being made in the first place.
This is identical to the problem with causal decision theory which goes “If determinism is true, I’m already certain to make my decision, so how can I worry about its causal impacts?”
The answer is that you swear the oath because you calculated what would happen if (by causal surgery) your decision procedure output something else. This calculation gets done regardless of determinism—it’s just how this decision procedure goes.
If it is indeed in your power to swear and execute such an oath, then “I will make an oath to simulate this event and make such-and-such changes” is a legitimate event that would impact any probability calculation. Before swearing the oath, there was still the probability of you swearing it in the future and executing it.
The probability of going to a tropical island given that the oath was made is likely higher than it was before the oath was made, but the only way it would be significantly higher is if there was a very low probability of the oath being made in the first place.
This is identical to the problem with causal decision theory which goes “If determinism is true, I’m already certain to make my decision, so how can I worry about its causal impacts?”
The answer is that you swear the oath because you calculated what would happen if (by causal surgery) your decision procedure output something else. This calculation gets done regardless of determinism—it’s just how this decision procedure goes.