What on earth does the following footnote mean? Are we back to consciousness where the "quantumbuck" stops? /LN
Understanding Deutsch's Probability in a Deterministic Multiverse by Hilary Greaves Footnote 16 The following objection is sometimes raised against the decision-theoretic approach: in an Everettian context, all outcomes of a decision are realized, and therefore it simply does not make sense to make choices, or to reason about how one should act. If that is correct, then while we may agree that probability can in principle be derived from rationality, this is of no use to the Everettian, since (it is claimed) the Everettian cannot make sense of rationality itself. If this was correct, it would be a pressing 'incoherence problem' for the decision-theoretic approach. The objection, however, is simply mistaken. The mistake arises from an assumption that decisions must be modelled as Everettian branching, with each possible outcome of the decision realized on some branch. This is not true, and it is not at all what is going on in the decision scenarios Deutsch and Wallace consider. Rather, the agent is making a genuine choice between quantum games, only one of which will be realized (namely, the chosen game). To be sure, each game consists of an array of branches, all of which will, if that game is chosen, be realized. But this does not mean that all games will be realized. It is no less coherent for an Everettian to have a preference ordering over quantum games than it is for an agent in a state of classical uncertainty to have a preference ordering over classical lotteries.