Abstract

Introducing The Rational Imagination, Ruth Byrne tells us that rational thought has turned out to be “more imaginative than cognitive scientists...supposed,” and—more to the point here—that “[I]maginative thought is more rational than scientists imagined”. It would be unwise to take this mini-manifesto too seriously. The claim to which Byrne actually gives sustained attention is less philosophically sexy and more solidly empirical. This book is primarily concerned with experimental evidence in support of the thesis that the particular counterfactual conjectures people entertain—‘If Mary had asked Peter to pick the peppers, he would have picked the peppers’—are governed by the same small set of psychological principles that influence inferential reasoning about them—‘Peter didn’t pick the peppers? Well, then, it stands to reason that Mary didn’t ask him to’. Byrne conjectures that this same small set of principles might also help in understanding how people creatively generate new members of a category, interpret novel phrases like ‘cactus fish’, and solve insight problems. By contrast, Byrne’s discussion of criteria for the rationality of counterfactual thought comes close to the end of the book and is notably modest and tentative. Perhaps counterfactual thought counts as rational if it is capable of producing the “best” judgments; perhaps the best counterfactual judgments are those that strike us as most plausible; perhaps plausibility is a hallmark of rationality because it is grounded in recognition of “fault lines in reality”. On the other hand, perhaps not. Counterfactual thoughts that paralyze people with regret are often compellingly plausible. Despite their plausibility, Byrne characterizes such “dysfunctional” counterfactuals as “irrational.” Perhaps this can be harmonized by the competence/performance distinction; perhaps a canny reader would be better advised to settle for the psychology.