How We Reason

by Philip N. Johnson-Laird

Good reasoning can lead to success; bad reasoning can lead to catastrophe. Yet, it's not obvious how we reason, and why we make mistakes - so much of our mental life goes on outside our awareness. In recent years huge strides have been made into developing a scientific understanding of reasoning. This book by one of the pioneers of the field, Philip Johnson-Laird, looks at the mental processes that underlie our reasoning. It provides the most accessible account yet of the science of reasoning.

We can all reason from our childhood onwards - but how? 'How We Reason' outlines a bold approach to understanding reasoning. According to this approach, we don't rely on the laws of logic or probability - we reason by thinking about what's possible, we reason by seeing what is common to the possibilities. As the book shows, this approach can answer many of the questions about how we reason, and what causes mistakes in our reasoning that can lead to disasters such as Chernobyl. It shows why our irrational fears may become psychological illnesses, why terrorists develop 'crazy' ideologies, and how we can act in order to improve our reasoning. The book ends by looking at the role of reasoning in three extraordinary case the Wright brothers' use of analogies in inventing their flyer, the cryptanalysts' deductions in breaking the German's Enigma code in World War II, and Dr. John Snow's inductive reasoning in discovering how cholera spread from one person to another.

Accessible, stimulating, and controversial, How we Reason presents a bold new approach to understanding one of the most intriguing facets of being human.

Genres: Psychology, Nonfiction, Philosophy, Neuroscience, Science

584 pages, Paperback

First published January 1, 2006

About the author

Philip N. Johnson-Laird is a professor at Princeton University's Department of Psychology and author of several notable books on human cognition and the psychology of reasoning.

Reviews

[TjeerdFokkens]

This book is very nice in that it contains many examples about reasoning both in the lab and in practice. The writing is good and lively and keeps the reader interested in the argument. A major -- and quite fundamental -- drawback, however, is that the theory of mental models is not well-defined; a problem which is common in the literature. This makes it difficult to see what the theory actually predicts. Instead, the book applies the vaguely formulated idea of mental models all too easily to a wide range of experiments, in hindsight. This is such a shame, as the theory, unless well-defined, could have the potential to explain the phenomena much more rigorously.
The conclusion is, in my opinion, that the theory of mental models needs to be formalised and then actively attempted to be falsified, after which a new book on the subject could be written.

[Alice Wardle]

I decided to give this one 5 stars because I love learning about reasoning and logic, and this included lots of excellent, valuable information.

I think the model theory of reasoning is interesting, plausible, though still quite vague. It explains how we reason quite well, but nothing is said about its implications. Given the comprehensive nature of the book, I would have liked to see some discussion on what the model theory means for perhaps AI, if the author considered that an important means, or about education, politics, or social science. Much is said about case studies of the past and how the model theory can be applied with little discussed about its future implications.

I can see it being of personal value. The model theory predicts how common errors in reasoning occur, and so being aware of how to reduce or prevent this from happening may allow me to reason more accurately in the future.

I felt as though the book was easy to follow, very well-written, though sometimes I forgot some terms or ideas as I was reading this for almost a year. As well as this, there were some points where I got lost somewhere in an explanation of something, and therefore couldn't understand a few paragraphs or pages. Though there were regular diagrams, I think some more abstract visuals with no words might have been helpful.

Overall, I enjoyed this book and found it very intriguing, and I recommend it to anyone with an interest in understanding a cognitive psychological approach to reasoning!