Right, so we need to figure out what kinds of reasoning by symmetry are allowed under perfect rationality (in all possible games, not just this one). For example, should a rational person cooperate in the Prisoner&#x27;s Dilemma because the opponent will be forced to cooperate by symmetry? In that case, won&#x27;t irrational people eat rational people for breakfast, thus devaluing the idea that rational behavior maximizes utility?<p>If you take the time to think it though, you might well reinvent superrationality, updateless decision theory and other fascinating things. In fact, you&#x27;ll quickly get to questions that I have no idea how to solve!