A review of empirical and theoretical work on reasoning and linguistic inference, which will be a useful introduction to the subject for students of language and thought. The book focuses on the relationship between what people do and what people are supposed to do when making inferences.

We propose that the pragmatic factors that mediate everyday deduction, such as alternative and disabling conditions (e.g. Cummins et al., 1991) and additional requirements (Byrne, 1989) exert their effects on specific inferences because of their perceived relevance to more general principles, which we term SuperPs. Support for this proposal was found first in two causal inference experiments, in which it was shown that specific inferences were mediated by factors that are relevant to a more general principle, while the same inferences (...) were unaffected by factors not relevant to the general principle. These results were extended to deontic inferences in two further experiments. Taken together, these findings show that unstated superordinate principles play a significant role in certain types of reasoning. Questions raised by the findings for the main theoretical approaches are discussed. (shrink)

This commentary focuses on the implications of practical reasoning research for the view of rationality in Stanovich & West's target article. Practical reasoning does not correlate with intelligence or other reasoning tasks. Explanation in decision making terms raises the issue of dilemmas, making it hard to specify the correct norm, when an action can satisfy or conflict with two equally justifiable goals.