I argue that some cases of delusions show the inadequacy of those theories of interpretation that rely on a necessary rationality constraint on belief ascription. In particular I challenge the view that irrational beliefs can be ascribed only against a general background of rationality. Subjects affected by delusions seem to be genuine believers and their behaviour can be successfully explained in intentional terms, but they do not meet those criteria that according to Davidson (1985a) need to be met for the (...) background of rationality to be in place. (shrink)

Suppose I am now making plans for next summer’s vacation. I can spend a week in Rome or on the Riviera, but not both. Either choice would be excellent, but after weighing various pros and cons, I decide that for my purposes Rome would be better. If I am rational, then, I must choose Rome. It is an assumption of standard decision theory that rationality requires maximizing: trying to get the maximum amount of whatever form of value we are after (...) (usually construed as “utility”). An alternative has been proposed, under the heading of “satisficing” – being satisfied with what suffices, as it were, or settling for an option that is “good enough” – but this may seem rational only when there are costs to determining which option is best that diminish the value of choosing it, to the point where the choice of a less good option really amounts to maximizing. Where there is no serious cost, even in time and effort, to getting hold of something better – a vacation in Rome rather than the Riviera – how could it be rational to turn it down? If we pay attention to the temporal standpoint from which a choice is made, though, satisficing makes good sense. It accords with our common appeal to thresholds: adequate levels of satisfaction or value, such that getting above them is not necessary, though it might be nice. Once we have reached a threshold, it is rational – meaning rationally permissible – to stop. Pushing further toward the best may also be permissible but is not rationally required, where we already have a good enough option in hand. So if offered a chance to move to Rome while already settled happily on the Riviera, I would not be irrational to turn the offer down, even if I grant that accepting it would make my vacation even better. (shrink)

Representation theorems are often taken to provide the foundations for decision theory. First, they are taken to characterize degrees of belief and utilities. Second, they are taken to justify two fundamental rules of rationality: that we should have probabilistic degrees of belief and that we should act as expected utility maximizers. We argue that representation theorems cannot serve either of these foundational purposes, and that recent attempts to defend the foundational importance of representation theorems are unsuccessful. As a result, we (...) should reject these claims, and lay the foundations of decision theory on firmer ground. (shrink)